Esempio n. 1
0
File: sorg2l.c Progetto: Booley/nbis
/* Subroutine */ int sorg2l_(int *m, int *n, int *k, real *a, 
	int *lda, real *tau, real *work, int *info)
{
/*  -- LAPACK routine (version 2.0) --   
       Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,   
       Courant Institute, Argonne National Lab, and Rice University   
       February 29, 1992   


    Purpose   
    =======   

    SORG2L generates an m by n real matrix Q with orthonormal columns,   
    which is defined as the last n columns of a product of k elementary   
    reflectors of order m   

          Q  =  H(k) . . . H(2) H(1)   

    as returned by SGEQLF.   

    Arguments   
    =========   

    M       (input) INTEGER   
            The number of rows of the matrix Q. M >= 0.   

    N       (input) INTEGER   
            The number of columns of the matrix Q. M >= N >= 0.   

    K       (input) INTEGER   
            The number of elementary reflectors whose product defines the 
  
            matrix Q. N >= K >= 0.   

    A       (input/output) REAL array, dimension (LDA,N)   
            On entry, the (n-k+i)-th column must contain the vector which 
  
            defines the elementary reflector H(i), for i = 1,2,...,k, as 
  
            returned by SGEQLF in the last k columns of its array   
            argument A.   
            On exit, the m by n matrix Q.   

    LDA     (input) INTEGER   
            The first dimension of the array A. LDA >= max(1,M).   

    TAU     (input) REAL array, dimension (K)   
            TAU(i) must contain the scalar factor of the elementary   
            reflector H(i), as returned by SGEQLF.   

    WORK    (workspace) REAL array, dimension (N)   

    INFO    (output) INTEGER   
            = 0: successful exit   
            < 0: if INFO = -i, the i-th argument has an illegal value   

    ===================================================================== 
  


       Test the input arguments   

    
   Parameter adjustments   
       Function Body */
    /* Table of constant values */
    static int c__1 = 1;
    
    /* System generated locals */
/*  Unused variables commented out by MDG on 03-09-05
    int a_dim1, a_offset;
*/
    int i__1, i__2, i__3;
    real r__1;
    /* Local variables */
    static int i, j, l;
    extern /* Subroutine */ int sscal_(int *, real *, real *, int *), 
	    slarf_(char *, int *, int *, real *, int *, real *, 
	    real *, int *, real *);
    static int ii;
    extern /* Subroutine */ int xerbla_(char *, int *);



#define TAU(I) tau[(I)-1]
#define WORK(I) work[(I)-1]

#define A(I,J) a[(I)-1 + ((J)-1)* ( *lda)]

    *info = 0;
    if (*m < 0) {
	*info = -1;
    } else if (*n < 0 || *n > *m) {
	*info = -2;
    } else if (*k < 0 || *k > *n) {
	*info = -3;
    } else if (*lda < max(1,*m)) {
	*info = -5;
    }
    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("SORG2L", &i__1);
	return 0;
    }

/*     Quick return if possible */

    if (*n <= 0) {
	return 0;
    }

/*     Initialise columns 1:n-k to columns of the unit matrix */

    i__1 = *n - *k;
    for (j = 1; j <= *n-*k; ++j) {
	i__2 = *m;
	for (l = 1; l <= *m; ++l) {
	    A(l,j) = 0.f;
/* L10: */
	}
	A(*m-*n+j,j) = 1.f;
/* L20: */
    }

    i__1 = *k;
    for (i = 1; i <= *k; ++i) {
	ii = *n - *k + i;

/*        Apply H(i) to A(1:m-k+i,1:n-k+i) from the left */

	A(*m-*n+ii,ii) = 1.f;
	i__2 = *m - *n + ii;
	i__3 = ii - 1;
	slarf_("Left", &i__2, &i__3, &A(1,ii), &c__1, &TAU(i), &A(1,1), lda, &WORK(1));
	i__2 = *m - *n + ii - 1;
	r__1 = -(doublereal)TAU(i);
	sscal_(&i__2, &r__1, &A(1,ii), &c__1);
	A(*m-*n+ii,ii) = 1.f - TAU(i);

/*        Set A(m-k+i+1:m,n-k+i) to zero */

	i__2 = *m;
	for (l = *m - *n + ii + 1; l <= *m; ++l) {
	    A(l,ii) = 0.f;
/* L30: */
	}
/* L40: */
    }
    return 0;

/*     End of SORG2L */

} /* sorg2l_ */
Esempio n. 2
0
/* Subroutine */ int slaqr2_(logical *wantt, logical *wantz, integer *n, 
	integer *ktop, integer *kbot, integer *nw, real *h__, integer *ldh, 
	integer *iloz, integer *ihiz, real *z__, integer *ldz, integer *ns, 
	integer *nd, real *sr, real *si, real *v, integer *ldv, integer *nh, 
	real *t, integer *ldt, integer *nv, real *wv, integer *ldwv, real *
	work, integer *lwork)
{
    /* System generated locals */
    integer h_dim1, h_offset, t_dim1, t_offset, v_dim1, v_offset, wv_dim1, 
	    wv_offset, z_dim1, z_offset, i__1, i__2, i__3, i__4;
    real r__1, r__2, r__3, r__4, r__5, r__6;

    /* Local variables */
    integer i__, j, k;
    real s, aa, bb, cc, dd, cs, sn;
    integer jw;
    real evi, evk, foo;
    integer kln;
    real tau, ulp;
    integer lwk1, lwk2;
    real beta;
    integer kend, kcol, info, ifst, ilst, ltop, krow;
    logical bulge;
    integer infqr;
    integer kwtop;
    real safmin;
    real safmax;
    logical sorted;
    real smlnum;
    integer lwkopt;

/*  -- LAPACK auxiliary routine (version 3.2.1)                        -- */
/*  -- April 2009                                                      -- */

/*     This subroutine is identical to SLAQR3 except that it avoids */
/*     recursion by calling SLAHQR instead of SLAQR4. */

/*     ****************************************************************** */
/*     Aggressive early deflation: */

/*     This subroutine accepts as input an upper Hessenberg matrix */
/*     H and performs an orthogonal similarity transformation */
/*     designed to detect and deflate fully converged eigenvalues from */
/*     a trailing principal submatrix.  On output H has been over- */
/*     written by a new Hessenberg matrix that is a perturbation of */
/*     an orthogonal similarity transformation of H.  It is to be */
/*     hoped that the final version of H has many zero subdiagonal */
/*     entries. */

/*     ****************************************************************** */
/*     WANTT   (input) LOGICAL */
/*          If .TRUE., then the Hessenberg matrix H is fully updated */
/*          so that the quasi-triangular Schur factor may be */
/*          computed (in cooperation with the calling subroutine). */
/*          If .FALSE., then only enough of H is updated to preserve */
/*          the eigenvalues. */

/*     WANTZ   (input) LOGICAL */
/*          If .TRUE., then the orthogonal matrix Z is updated so */
/*          so that the orthogonal Schur factor may be computed */
/*          (in cooperation with the calling subroutine). */
/*          If .FALSE., then Z is not referenced. */

/*     N       (input) INTEGER */
/*          The order of the matrix H and (if WANTZ is .TRUE.) the */
/*          order of the orthogonal matrix Z. */

/*     KTOP    (input) INTEGER */
/*          It is assumed that either KTOP = 1 or H(KTOP,KTOP-1)=0. */
/*          KBOT and KTOP together determine an isolated block */
/*          along the diagonal of the Hessenberg matrix. */

/*     KBOT    (input) INTEGER */
/*          It is assumed without a check that either */
/*          KBOT = N or H(KBOT+1,KBOT)=0.  KBOT and KTOP together */
/*          determine an isolated block along the diagonal of the */
/*          Hessenberg matrix. */

/*     NW      (input) INTEGER */
/*          Deflation window size.  1 .LE. NW .LE. (KBOT-KTOP+1). */

/*     H       (input/output) REAL array, dimension (LDH,N) */
/*          On input the initial N-by-N section of H stores the */
/*          Hessenberg matrix undergoing aggressive early deflation. */
/*          On output H has been transformed by an orthogonal */
/*          similarity transformation, perturbed, and the returned */
/*          to Hessenberg form that (it is to be hoped) has some */
/*          zero subdiagonal entries. */

/*     LDH     (input) integer */
/*          Leading dimension of H just as declared in the calling */
/*          subroutine.  N .LE. LDH */

/*     ILOZ    (input) INTEGER */
/*     IHIZ    (input) INTEGER */
/*          Specify the rows of Z to which transformations must be */

/*     Z       (input/output) REAL array, dimension (LDZ,N) */
/*          IF WANTZ is .TRUE., then on output, the orthogonal */
/*          similarity transformation mentioned above has been */
/*          accumulated into Z(ILOZ:IHIZ,ILO:IHI) from the right. */
/*          If WANTZ is .FALSE., then Z is unreferenced. */

/*     LDZ     (input) integer */
/*          The leading dimension of Z just as declared in the */
/*          calling subroutine.  1 .LE. LDZ. */

/*     NS      (output) integer */
/*          The number of unconverged (ie approximate) eigenvalues */
/*          returned in SR and SI that may be used as shifts by the */
/*          calling subroutine. */

/*     ND      (output) integer */
/*          The number of converged eigenvalues uncovered by this */
/*          subroutine. */

/*     SR      (output) REAL array, dimension KBOT */
/*     SI      (output) REAL array, dimension KBOT */
/*          On output, the real and imaginary parts of approximate */
/*          eigenvalues that may be used for shifts are stored in */
/*          SR(KBOT-ND-NS+1) through SR(KBOT-ND) and */
/*          SI(KBOT-ND-NS+1) through SI(KBOT-ND), respectively. */
/*          The real and imaginary parts of converged eigenvalues */
/*          are stored in SR(KBOT-ND+1) through SR(KBOT) and */
/*          SI(KBOT-ND+1) through SI(KBOT), respectively. */

/*     V       (workspace) REAL array, dimension (LDV,NW) */
/*          An NW-by-NW work array. */

/*     LDV     (input) integer scalar */
/*          The leading dimension of V just as declared in the */
/*          calling subroutine.  NW .LE. LDV */

/*     NH      (input) integer scalar */
/*          The number of columns of T.  NH.GE.NW. */

/*     T       (workspace) REAL array, dimension (LDT,NW) */

/*     LDT     (input) integer */
/*          The leading dimension of T just as declared in the */
/*          calling subroutine.  NW .LE. LDT */

/*     NV      (input) integer */
/*          The number of rows of work array WV available for */
/*          workspace.  NV.GE.NW. */

/*     WV      (workspace) REAL array, dimension (LDWV,NW) */

/*     LDWV    (input) integer */
/*          The leading dimension of W just as declared in the */
/*          calling subroutine.  NW .LE. LDV */

/*     WORK    (workspace) REAL array, dimension LWORK. */
/*          On exit, WORK(1) is set to an estimate of the optimal value */
/*          of LWORK for the given values of N, NW, KTOP and KBOT. */

/*     LWORK   (input) integer */
/*          The dimension of the work array WORK.  LWORK = 2*NW */
/*          suffices, but greater efficiency may result from larger */
/*          values of LWORK. */

/*          If LWORK = -1, then a workspace query is assumed; SLAQR2 */
/*          only estimates the optimal workspace size for the given */
/*          values of N, NW, KTOP and KBOT.  The estimate is returned */
/*          in WORK(1).  No error message related to LWORK is issued */
/*          by XERBLA.  Neither H nor Z are accessed. */

/*     ================================================================ */
/*     Based on contributions by */
/*        Karen Braman and Ralph Byers, Department of Mathematics, */
/*        University of Kansas, USA */

/*     ================================================================ */

/*     ==== Estimate optimal workspace. ==== */

    /* Parameter adjustments */
    h_dim1 = *ldh;
    h_offset = 1 + h_dim1;
    h__ -= h_offset;
    z_dim1 = *ldz;
    z_offset = 1 + z_dim1;
    z__ -= z_offset;
    --sr;
    --si;
    v_dim1 = *ldv;
    v_offset = 1 + v_dim1;
    v -= v_offset;
    t_dim1 = *ldt;
    t_offset = 1 + t_dim1;
    t -= t_offset;
    wv_dim1 = *ldwv;
    wv_offset = 1 + wv_dim1;
    wv -= wv_offset;
    --work;

    /* Function Body */
/* Computing MIN */
    i__1 = *nw, i__2 = *kbot - *ktop + 1;
    jw = min(i__1,i__2);
    if (jw <= 2) {
	lwkopt = 1;
    } else {

/*        ==== Workspace query call to SGEHRD ==== */

	i__1 = jw - 1;
	sgehrd_(&jw, &c__1, &i__1, &t[t_offset], ldt, &work[1], &work[1], &
		c_n1, &info);
	lwk1 = (integer) work[1];

/*        ==== Workspace query call to SORMHR ==== */

	i__1 = jw - 1;
	sormhr_("R", "N", &jw, &jw, &c__1, &i__1, &t[t_offset], ldt, &work[1], 
		 &v[v_offset], ldv, &work[1], &c_n1, &info);
	lwk2 = (integer) work[1];

/*        ==== Optimal workspace ==== */

	lwkopt = jw + max(lwk1,lwk2);
    }

/*     ==== Quick return in case of workspace query. ==== */

    if (*lwork == -1) {
	work[1] = (real) lwkopt;
	return 0;
    }

    *ns = 0;
    *nd = 0;
    work[1] = 1.f;
    if (*ktop > *kbot) {
	return 0;
    }
    if (*nw < 1) {
	return 0;
    }

/*     ==== Machine constants ==== */

    safmin = slamch_("SAFE MINIMUM");
    safmax = 1.f / safmin;
    slabad_(&safmin, &safmax);
    ulp = slamch_("PRECISION");
    smlnum = safmin * ((real) (*n) / ulp);

/*     ==== Setup deflation window ==== */

/* Computing MIN */
    i__1 = *nw, i__2 = *kbot - *ktop + 1;
    jw = min(i__1,i__2);
    kwtop = *kbot - jw + 1;
    if (kwtop == *ktop) {
	s = 0.f;
    } else {
	s = h__[kwtop + (kwtop - 1) * h_dim1];
    }

    if (*kbot == kwtop) {

/*        ==== 1-by-1 deflation window: not much to do ==== */

	sr[kwtop] = h__[kwtop + kwtop * h_dim1];
	si[kwtop] = 0.f;
	*ns = 1;
	*nd = 0;
/* Computing MAX */
	r__2 = smlnum, r__3 = ulp * (r__1 = h__[kwtop + kwtop * h_dim1], dabs(
		r__1));
	if (dabs(s) <= dmax(r__2,r__3)) {
	    *ns = 0;
	    *nd = 1;
	    if (kwtop > *ktop) {
		h__[kwtop + (kwtop - 1) * h_dim1] = 0.f;
	    }
	}
	work[1] = 1.f;
	return 0;
    }

/*     ==== Convert to spike-triangular form.  (In case of a */
/*     .    rare QR failure, this routine continues to do */
/*     .    aggressive early deflation using that part of */
/*     .    the deflation window that converged using INFQR */
/*     .    here and there to keep track.) ==== */

    slacpy_("U", &jw, &jw, &h__[kwtop + kwtop * h_dim1], ldh, &t[t_offset], 
	    ldt);
    i__1 = jw - 1;
    i__2 = *ldh + 1;
    i__3 = *ldt + 1;
    scopy_(&i__1, &h__[kwtop + 1 + kwtop * h_dim1], &i__2, &t[t_dim1 + 2], &
	    i__3);

    slaset_("A", &jw, &jw, &c_b12, &c_b13, &v[v_offset], ldv);
    slahqr_(&c_true, &c_true, &jw, &c__1, &jw, &t[t_offset], ldt, &sr[kwtop], 
	    &si[kwtop], &c__1, &jw, &v[v_offset], ldv, &infqr);

/*     ==== STREXC needs a clean margin near the diagonal ==== */

    i__1 = jw - 3;
    for (j = 1; j <= i__1; ++j) {
	t[j + 2 + j * t_dim1] = 0.f;
	t[j + 3 + j * t_dim1] = 0.f;
    }
    if (jw > 2) {
	t[jw + (jw - 2) * t_dim1] = 0.f;
    }

/*     ==== Deflation detection loop ==== */

    *ns = jw;
    ilst = infqr + 1;
L20:
    if (ilst <= *ns) {
	if (*ns == 1) {
	    bulge = FALSE_;
	} else {
	    bulge = t[*ns + (*ns - 1) * t_dim1] != 0.f;
	}

/*        ==== Small spike tip test for deflation ==== */

	if (! bulge) {

/*           ==== Real eigenvalue ==== */

	    foo = (r__1 = t[*ns + *ns * t_dim1], dabs(r__1));
	    if (foo == 0.f) {
		foo = dabs(s);
	    }
/* Computing MAX */
	    r__2 = smlnum, r__3 = ulp * foo;
	    if ((r__1 = s * v[*ns * v_dim1 + 1], dabs(r__1)) <= dmax(r__2,
		    r__3)) {

/*              ==== Deflatable ==== */

		--(*ns);
	    } else {

/*              ==== Undeflatable.   Move it up out of the way. */
/*              .    (STREXC can not fail in this case.) ==== */

		ifst = *ns;
		strexc_("V", &jw, &t[t_offset], ldt, &v[v_offset], ldv, &ifst, 
			 &ilst, &work[1], &info);
		++ilst;
	    }
	} else {

/*           ==== Complex conjugate pair ==== */

	    foo = (r__3 = t[*ns + *ns * t_dim1], dabs(r__3)) + sqrt((r__1 = t[
		    *ns + (*ns - 1) * t_dim1], dabs(r__1))) * sqrt((r__2 = t[*
		    ns - 1 + *ns * t_dim1], dabs(r__2)));
	    if (foo == 0.f) {
		foo = dabs(s);
	    }
/* Computing MAX */
	    r__3 = (r__1 = s * v[*ns * v_dim1 + 1], dabs(r__1)), r__4 = (r__2 
		    = s * v[(*ns - 1) * v_dim1 + 1], dabs(r__2));
/* Computing MAX */
	    r__5 = smlnum, r__6 = ulp * foo;
	    if (dmax(r__3,r__4) <= dmax(r__5,r__6)) {

/*              ==== Deflatable ==== */

		*ns += -2;
	    } else {

/*              ==== Undeflatable. Move them up out of the way. */
/*              .    Fortunately, STREXC does the right thing with */
/*              .    ILST in case of a rare exchange failure. ==== */

		ifst = *ns;
		strexc_("V", &jw, &t[t_offset], ldt, &v[v_offset], ldv, &ifst, 
			 &ilst, &work[1], &info);
		ilst += 2;
	    }
	}

/*        ==== End deflation detection loop ==== */

	goto L20;
    }

/*        ==== Return to Hessenberg form ==== */

    if (*ns == 0) {
	s = 0.f;
    }

    if (*ns < jw) {

/*        ==== sorting diagonal blocks of T improves accuracy for */
/*        .    graded matrices.  Bubble sort deals well with */
/*        .    exchange failures. ==== */

	sorted = FALSE_;
	i__ = *ns + 1;
L30:
	if (sorted) {
	    goto L50;
	}
	sorted = TRUE_;

	kend = i__ - 1;
	i__ = infqr + 1;
	if (i__ == *ns) {
	    k = i__ + 1;
	} else if (t[i__ + 1 + i__ * t_dim1] == 0.f) {
	    k = i__ + 1;
	} else {
	    k = i__ + 2;
	}
L40:
	if (k <= kend) {
	    if (k == i__ + 1) {
		evi = (r__1 = t[i__ + i__ * t_dim1], dabs(r__1));
	    } else {
		evi = (r__3 = t[i__ + i__ * t_dim1], dabs(r__3)) + sqrt((r__1 
			= t[i__ + 1 + i__ * t_dim1], dabs(r__1))) * sqrt((
			r__2 = t[i__ + (i__ + 1) * t_dim1], dabs(r__2)));
	    }

	    if (k == kend) {
		evk = (r__1 = t[k + k * t_dim1], dabs(r__1));
	    } else if (t[k + 1 + k * t_dim1] == 0.f) {
		evk = (r__1 = t[k + k * t_dim1], dabs(r__1));
	    } else {
		evk = (r__3 = t[k + k * t_dim1], dabs(r__3)) + sqrt((r__1 = t[
			k + 1 + k * t_dim1], dabs(r__1))) * sqrt((r__2 = t[k 
			+ (k + 1) * t_dim1], dabs(r__2)));
	    }

	    if (evi >= evk) {
		i__ = k;
	    } else {
		sorted = FALSE_;
		ifst = i__;
		ilst = k;
		strexc_("V", &jw, &t[t_offset], ldt, &v[v_offset], ldv, &ifst, 
			 &ilst, &work[1], &info);
		if (info == 0) {
		    i__ = ilst;
		} else {
		    i__ = k;
		}
	    }
	    if (i__ == kend) {
		k = i__ + 1;
	    } else if (t[i__ + 1 + i__ * t_dim1] == 0.f) {
		k = i__ + 1;
	    } else {
		k = i__ + 2;
	    }
	    goto L40;
	}
	goto L30;
L50:
	;
    }

/*     ==== Restore shift/eigenvalue array from T ==== */

    i__ = jw;
L60:
    if (i__ >= infqr + 1) {
	if (i__ == infqr + 1) {
	    sr[kwtop + i__ - 1] = t[i__ + i__ * t_dim1];
	    si[kwtop + i__ - 1] = 0.f;
	    --i__;
	} else if (t[i__ + (i__ - 1) * t_dim1] == 0.f) {
	    sr[kwtop + i__ - 1] = t[i__ + i__ * t_dim1];
	    si[kwtop + i__ - 1] = 0.f;
	    --i__;
	} else {
	    aa = t[i__ - 1 + (i__ - 1) * t_dim1];
	    cc = t[i__ + (i__ - 1) * t_dim1];
	    bb = t[i__ - 1 + i__ * t_dim1];
	    dd = t[i__ + i__ * t_dim1];
	    slanv2_(&aa, &bb, &cc, &dd, &sr[kwtop + i__ - 2], &si[kwtop + i__ 
		    - 2], &sr[kwtop + i__ - 1], &si[kwtop + i__ - 1], &cs, &
		    sn);
	    i__ += -2;
	}
	goto L60;
    }

    if (*ns < jw || s == 0.f) {
	if (*ns > 1 && s != 0.f) {

/*           ==== Reflect spike back into lower triangle ==== */

	    scopy_(ns, &v[v_offset], ldv, &work[1], &c__1);
	    beta = work[1];
	    slarfg_(ns, &beta, &work[2], &c__1, &tau);
	    work[1] = 1.f;

	    i__1 = jw - 2;
	    i__2 = jw - 2;
	    slaset_("L", &i__1, &i__2, &c_b12, &c_b12, &t[t_dim1 + 3], ldt);

	    slarf_("L", ns, &jw, &work[1], &c__1, &tau, &t[t_offset], ldt, &
		    work[jw + 1]);
	    slarf_("R", ns, ns, &work[1], &c__1, &tau, &t[t_offset], ldt, &
		    work[jw + 1]);
	    slarf_("R", &jw, ns, &work[1], &c__1, &tau, &v[v_offset], ldv, &
		    work[jw + 1]);

	    i__1 = *lwork - jw;
	    sgehrd_(&jw, &c__1, ns, &t[t_offset], ldt, &work[1], &work[jw + 1]
, &i__1, &info);
	}

/*        ==== Copy updated reduced window into place ==== */

	if (kwtop > 1) {
	    h__[kwtop + (kwtop - 1) * h_dim1] = s * v[v_dim1 + 1];
	}
	slacpy_("U", &jw, &jw, &t[t_offset], ldt, &h__[kwtop + kwtop * h_dim1]
, ldh);
	i__1 = jw - 1;
	i__2 = *ldt + 1;
	i__3 = *ldh + 1;
	scopy_(&i__1, &t[t_dim1 + 2], &i__2, &h__[kwtop + 1 + kwtop * h_dim1], 
		 &i__3);

/*        ==== Accumulate orthogonal matrix in order update */
/*        .    H and Z, if requested.  ==== */

	if (*ns > 1 && s != 0.f) {
	    i__1 = *lwork - jw;
	    sormhr_("R", "N", &jw, ns, &c__1, ns, &t[t_offset], ldt, &work[1], 
		     &v[v_offset], ldv, &work[jw + 1], &i__1, &info);
	}

/*        ==== Update vertical slab in H ==== */

	if (*wantt) {
	    ltop = 1;
	} else {
	    ltop = *ktop;
	}
	i__1 = kwtop - 1;
	i__2 = *nv;
	for (krow = ltop; i__2 < 0 ? krow >= i__1 : krow <= i__1; krow += 
		i__2) {
/* Computing MIN */
	    i__3 = *nv, i__4 = kwtop - krow;
	    kln = min(i__3,i__4);
	    sgemm_("N", "N", &kln, &jw, &jw, &c_b13, &h__[krow + kwtop * 
		    h_dim1], ldh, &v[v_offset], ldv, &c_b12, &wv[wv_offset], 
		    ldwv);
	    slacpy_("A", &kln, &jw, &wv[wv_offset], ldwv, &h__[krow + kwtop * 
		    h_dim1], ldh);
	}

/*        ==== Update horizontal slab in H ==== */

	if (*wantt) {
	    i__2 = *n;
	    i__1 = *nh;
	    for (kcol = *kbot + 1; i__1 < 0 ? kcol >= i__2 : kcol <= i__2; 
		    kcol += i__1) {
/* Computing MIN */
		i__3 = *nh, i__4 = *n - kcol + 1;
		kln = min(i__3,i__4);
		sgemm_("C", "N", &jw, &kln, &jw, &c_b13, &v[v_offset], ldv, &
			h__[kwtop + kcol * h_dim1], ldh, &c_b12, &t[t_offset], 
			 ldt);
		slacpy_("A", &jw, &kln, &t[t_offset], ldt, &h__[kwtop + kcol *
			 h_dim1], ldh);
	    }
	}

/*        ==== Update vertical slab in Z ==== */

	if (*wantz) {
	    i__1 = *ihiz;
	    i__2 = *nv;
	    for (krow = *iloz; i__2 < 0 ? krow >= i__1 : krow <= i__1; krow +=
		     i__2) {
/* Computing MIN */
		i__3 = *nv, i__4 = *ihiz - krow + 1;
		kln = min(i__3,i__4);
		sgemm_("N", "N", &kln, &jw, &jw, &c_b13, &z__[krow + kwtop * 
			z_dim1], ldz, &v[v_offset], ldv, &c_b12, &wv[
			wv_offset], ldwv);
		slacpy_("A", &kln, &jw, &wv[wv_offset], ldwv, &z__[krow + 
			kwtop * z_dim1], ldz);
	    }
	}
    }

    *nd = jw - *ns;

/*     .    INFQR from the spike length takes care */
/*     .    of the case of a rare QR failure while */
/*     .    calculating eigenvalues of the deflation */
/*     .    window.)  ==== */

    *ns -= infqr;

/*      ==== Return optimal workspace. ==== */

    work[1] = (real) lwkopt;

/*     ==== End of SLAQR2 ==== */

    return 0;
} /* slaqr2_ */
Esempio n. 3
0
/* Subroutine */ int sorm2l_(char *side, char *trans, integer *m, integer *n, 
	integer *k, real *a, integer *lda, real *tau, real *c__, integer *ldc, 
	 real *work, integer *info)
{
    /* System generated locals */
    integer a_dim1, a_offset, c_dim1, c_offset, i__1, i__2;

    /* Local variables */
    integer i__, i1, i2, i3, mi, ni, nq;
    real aii;
    logical left;
    logical notran;

/*  -- LAPACK routine (version 3.2) -- */
/*     November 2006 */

/*  Purpose */
/*  ======= */

/*  SORM2L overwrites the general real m by n matrix C with */

/*        Q * C  if SIDE = 'L' and TRANS = 'N', or */

/*        Q'* C  if SIDE = 'L' and TRANS = 'T', or */

/*        C * Q  if SIDE = 'R' and TRANS = 'N', or */

/*        C * Q' if SIDE = 'R' and TRANS = 'T', */

/*  where Q is a real orthogonal matrix defined as the product of k */
/*  elementary reflectors */

/*        Q = H(k) . . . H(2) H(1) */

/*  as returned by SGEQLF. Q is of order m if SIDE = 'L' and of order n */
/*  if SIDE = 'R'. */

/*  Arguments */
/*  ========= */

/*  SIDE    (input) CHARACTER*1 */
/*          = 'L': apply Q or Q' from the Left */
/*          = 'R': apply Q or Q' from the Right */

/*  TRANS   (input) CHARACTER*1 */
/*          = 'N': apply Q  (No transpose) */
/*          = 'T': apply Q' (Transpose) */

/*  M       (input) INTEGER */
/*          The number of rows of the matrix C. M >= 0. */

/*  N       (input) INTEGER */
/*          The number of columns of the matrix C. N >= 0. */

/*  K       (input) INTEGER */
/*          The number of elementary reflectors whose product defines */
/*          the matrix Q. */
/*          If SIDE = 'L', M >= K >= 0; */
/*          if SIDE = 'R', N >= K >= 0. */

/*  A       (input) REAL array, dimension (LDA,K) */
/*          The i-th column must contain the vector which defines the */
/*          SGEQLF in the last k columns of its array argument A. */
/*          A is modified by the routine but restored on exit. */

/*  LDA     (input) INTEGER */
/*          The leading dimension of the array A. */
/*          If SIDE = 'L', LDA >= max(1,M); */
/*          if SIDE = 'R', LDA >= max(1,N). */

/*  TAU     (input) REAL array, dimension (K) */
/*          TAU(i) must contain the scalar factor of the elementary */
/*          reflector H(i), as returned by SGEQLF. */

/*  C       (input/output) REAL array, dimension (LDC,N) */
/*          On entry, the m by n matrix C. */
/*          On exit, C is overwritten by Q*C or Q'*C or C*Q' or C*Q. */

/*  LDC     (input) INTEGER */
/*          The leading dimension of the array C. LDC >= max(1,M). */

/*  WORK    (workspace) REAL array, dimension */
/*                                   (N) if SIDE = 'L', */
/*                                   (M) if SIDE = 'R' */

/*  INFO    (output) INTEGER */
/*          = 0: successful exit */
/*          < 0: if INFO = -i, the i-th argument had an illegal value */

/*  ===================================================================== */

/*     Test the input arguments */

    /* Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    --tau;
    c_dim1 = *ldc;
    c_offset = 1 + c_dim1;
    c__ -= c_offset;
    --work;

    /* Function Body */
    *info = 0;
    left = lsame_(side, "L");
    notran = lsame_(trans, "N");

/*     NQ is the order of Q */

    if (left) {
	nq = *m;
    } else {
	nq = *n;
    }
    if (! left && ! lsame_(side, "R")) {
	*info = -1;
    } else if (! notran && ! lsame_(trans, "T")) {
	*info = -2;
    } else if (*m < 0) {
	*info = -3;
    } else if (*n < 0) {
	*info = -4;
    } else if (*k < 0 || *k > nq) {
	*info = -5;
    } else if (*lda < max(1,nq)) {
	*info = -7;
    } else if (*ldc < max(1,*m)) {
	*info = -10;
    }
    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("SORM2L", &i__1);
	return 0;
    }

/*     Quick return if possible */

    if (*m == 0 || *n == 0 || *k == 0) {
	return 0;
    }

    if (left && notran || ! left && ! notran) {
	i1 = 1;
	i2 = *k;
	i3 = 1;
    } else {
	i1 = *k;
	i2 = 1;
	i3 = -1;
    }

    if (left) {
	ni = *n;
    } else {
	mi = *m;
    }

    i__1 = i2;
    i__2 = i3;
    for (i__ = i1; i__2 < 0 ? i__ >= i__1 : i__ <= i__1; i__ += i__2) {
	if (left) {

/*           H(i) is applied to C(1:m-k+i,1:n) */

	    mi = *m - *k + i__;
	} else {

/*           H(i) is applied to C(1:m,1:n-k+i) */

	    ni = *n - *k + i__;
	}

/*        Apply H(i) */

	aii = a[nq - *k + i__ + i__ * a_dim1];
	a[nq - *k + i__ + i__ * a_dim1] = 1.f;
	slarf_(side, &mi, &ni, &a[i__ * a_dim1 + 1], &c__1, &tau[i__], &c__[
		c_offset], ldc, &work[1]);
	a[nq - *k + i__ + i__ * a_dim1] = aii;
    }
    return 0;

/*     End of SORM2L */

} /* sorm2l_ */
Esempio n. 4
0
/* Subroutine */ int sorml2_(char *side, char *trans, integer *m, integer *n, 
	integer *k, real *a, integer *lda, real *tau, real *c, integer *ldc, 
	real *work, integer *info)
{
/*  -- LAPACK routine (version 2.0) --   
       Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,   
       Courant Institute, Argonne National Lab, and Rice University   
       February 29, 1992   


    Purpose   
    =======   

    SORML2 overwrites the general real m by n matrix C with   

          Q * C  if SIDE = 'L' and TRANS = 'N', or   

          Q'* C  if SIDE = 'L' and TRANS = 'T', or   

          C * Q  if SIDE = 'R' and TRANS = 'N', or   

          C * Q' if SIDE = 'R' and TRANS = 'T',   

    where Q is a real orthogonal matrix defined as the product of k   
    elementary reflectors   

          Q = H(k) . . . H(2) H(1)   

    as returned by SGELQF. Q is of order m if SIDE = 'L' and of order n   
    if SIDE = 'R'.   

    Arguments   
    =========   

    SIDE    (input) CHARACTER*1   
            = 'L': apply Q or Q' from the Left   
            = 'R': apply Q or Q' from the Right   

    TRANS   (input) CHARACTER*1   
            = 'N': apply Q  (No transpose)   
            = 'T': apply Q' (Transpose)   

    M       (input) INTEGER   
            The number of rows of the matrix C. M >= 0.   

    N       (input) INTEGER   
            The number of columns of the matrix C. N >= 0.   

    K       (input) INTEGER   
            The number of elementary reflectors whose product defines   
            the matrix Q.   
            If SIDE = 'L', M >= K >= 0;   
            if SIDE = 'R', N >= K >= 0.   

    A       (input) REAL array, dimension   
                                 (LDA,M) if SIDE = 'L',   
                                 (LDA,N) if SIDE = 'R'   
            The i-th row must contain the vector which defines the   
            elementary reflector H(i), for i = 1,2,...,k, as returned by 
  
            SGELQF in the first k rows of its array argument A.   
            A is modified by the routine but restored on exit.   

    LDA     (input) INTEGER   
            The leading dimension of the array A. LDA >= max(1,K).   

    TAU     (input) REAL array, dimension (K)   
            TAU(i) must contain the scalar factor of the elementary   
            reflector H(i), as returned by SGELQF.   

    C       (input/output) REAL array, dimension (LDC,N)   
            On entry, the m by n matrix C.   
            On exit, C is overwritten by Q*C or Q'*C or C*Q' or C*Q.   

    LDC     (input) INTEGER   
            The leading dimension of the array C. LDC >= max(1,M).   

    WORK    (workspace) REAL array, dimension   
                                     (N) if SIDE = 'L',   
                                     (M) if SIDE = 'R'   

    INFO    (output) INTEGER   
            = 0: successful exit   
            < 0: if INFO = -i, the i-th argument had an illegal value   

    ===================================================================== 
  


       Test the input arguments   

    
   Parameter adjustments   
       Function Body */
    /* System generated locals */
    integer a_dim1, a_offset, c_dim1, c_offset, i__1, i__2;
    /* Local variables */
    static logical left;
    static integer i;
    extern logical lsame_(char *, char *);
    extern /* Subroutine */ int slarf_(char *, integer *, integer *, real *, 
	    integer *, real *, real *, integer *, real *);
    static integer i1, i2, i3, ic, jc, mi, ni, nq;
    extern /* Subroutine */ int xerbla_(char *, integer *);
    static logical notran;
    static real aii;


#define TAU(I) tau[(I)-1]
#define WORK(I) work[(I)-1]

#define A(I,J) a[(I)-1 + ((J)-1)* ( *lda)]
#define C(I,J) c[(I)-1 + ((J)-1)* ( *ldc)]

    *info = 0;
    left = lsame_(side, "L");
    notran = lsame_(trans, "N");

/*     NQ is the order of Q */

    if (left) {
	nq = *m;
    } else {
	nq = *n;
    }
    if (! left && ! lsame_(side, "R")) {
	*info = -1;
    } else if (! notran && ! lsame_(trans, "T")) {
	*info = -2;
    } else if (*m < 0) {
	*info = -3;
    } else if (*n < 0) {
	*info = -4;
    } else if (*k < 0 || *k > nq) {
	*info = -5;
    } else if (*lda < max(1,*k)) {
	*info = -7;
    } else if (*ldc < max(1,*m)) {
	*info = -10;
    }
    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("SORML2", &i__1);
	return 0;
    }

/*     Quick return if possible */

    if (*m == 0 || *n == 0 || *k == 0) {
	return 0;
    }

    if (left && notran || ! left && ! notran) {
	i1 = 1;
	i2 = *k;
	i3 = 1;
    } else {
	i1 = *k;
	i2 = 1;
	i3 = -1;
    }

    if (left) {
	ni = *n;
	jc = 1;
    } else {
	mi = *m;
	ic = 1;
    }

    i__1 = i2;
    i__2 = i3;
    for (i = i1; i3 < 0 ? i >= i2 : i <= i2; i += i3) {
	if (left) {

/*           H(i) is applied to C(i:m,1:n) */

	    mi = *m - i + 1;
	    ic = i;
	} else {

/*           H(i) is applied to C(1:m,i:n) */

	    ni = *n - i + 1;
	    jc = i;
	}

/*        Apply H(i) */

	aii = A(i,i);
	A(i,i) = 1.f;
	slarf_(side, &mi, &ni, &A(i,i), lda, &TAU(i), &C(ic,jc), ldc, &WORK(1));
	A(i,i) = aii;
/* L10: */
    }
    return 0;

/*     End of SORML2 */

} /* sorml2_ */
Esempio n. 5
0
/* Subroutine */
int sgehd2_(integer *n, integer *ilo, integer *ihi, real *a, integer *lda, real *tau, real *work, integer *info)
{
    /* System generated locals */
    integer a_dim1, a_offset, i__1, i__2, i__3;
    /* Local variables */
    integer i__;
    real aii;
    extern /* Subroutine */
    int slarf_(char *, integer *, integer *, real *, integer *, real *, real *, integer *, real *), xerbla_( char *, integer *), slarfg_(integer *, real *, real *, integer *, real *);
    /* -- LAPACK computational routine (version 3.4.2) -- */
    /* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
    /* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
    /* September 2012 */
    /* .. Scalar Arguments .. */
    /* .. */
    /* .. Array Arguments .. */
    /* .. */
    /* ===================================================================== */
    /* .. Parameters .. */
    /* .. */
    /* .. Local Scalars .. */
    /* .. */
    /* .. External Subroutines .. */
    /* .. */
    /* .. Intrinsic Functions .. */
    /* .. */
    /* .. Executable Statements .. */
    /* Test the input parameters */
    /* Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    --tau;
    --work;
    /* Function Body */
    *info = 0;
    if (*n < 0)
    {
        *info = -1;
    }
    else if (*ilo < 1 || *ilo > max(1,*n))
    {
        *info = -2;
    }
    else if (*ihi < min(*ilo,*n) || *ihi > *n)
    {
        *info = -3;
    }
    else if (*lda < max(1,*n))
    {
        *info = -5;
    }
    if (*info != 0)
    {
        i__1 = -(*info);
        xerbla_("SGEHD2", &i__1);
        return 0;
    }
    i__1 = *ihi - 1;
    for (i__ = *ilo;
            i__ <= i__1;
            ++i__)
    {
        /* Compute elementary reflector H(i) to annihilate A(i+2:ihi,i) */
        i__2 = *ihi - i__;
        /* Computing MIN */
        i__3 = i__ + 2;
        slarfg_(&i__2, &a[i__ + 1 + i__ * a_dim1], &a[min(i__3,*n) + i__ * a_dim1], &c__1, &tau[i__]);
        aii = a[i__ + 1 + i__ * a_dim1];
        a[i__ + 1 + i__ * a_dim1] = 1.f;
        /* Apply H(i) to A(1:ihi,i+1:ihi) from the right */
        i__2 = *ihi - i__;
        slarf_("Right", ihi, &i__2, &a[i__ + 1 + i__ * a_dim1], &c__1, &tau[ i__], &a[(i__ + 1) * a_dim1 + 1], lda, &work[1]);
        /* Apply H(i) to A(i+1:ihi,i+1:n) from the left */
        i__2 = *ihi - i__;
        i__3 = *n - i__;
        slarf_("Left", &i__2, &i__3, &a[i__ + 1 + i__ * a_dim1], &c__1, &tau[ i__], &a[i__ + 1 + (i__ + 1) * a_dim1], lda, &work[1]);
        a[i__ + 1 + i__ * a_dim1] = aii;
        /* L10: */
    }
    return 0;
    /* End of SGEHD2 */
}
Esempio n. 6
0
/* Subroutine */ int sgehd2_(integer *n, integer *ilo, integer *ihi, real *a, 
	integer *lda, real *tau, real *work, integer *info)
{
/*  -- LAPACK routine (version 3.0) --   
       Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,   
       Courant Institute, Argonne National Lab, and Rice University   
       October 31, 1992   


    Purpose   
    =======   

    SGEHD2 reduces a real general matrix A to upper Hessenberg form H by   
    an orthogonal similarity transformation:  Q' * A * Q = H .   

    Arguments   
    =========   

    N       (input) INTEGER   
            The order of the matrix A.  N >= 0.   

    ILO     (input) INTEGER   
    IHI     (input) INTEGER   
            It is assumed that A is already upper triangular in rows   
            and columns 1:ILO-1 and IHI+1:N. ILO and IHI are normally   
            set by a previous call to SGEBAL; otherwise they should be   
            set to 1 and N respectively. See Further Details.   
            1 <= ILO <= IHI <= max(1,N).   

    A       (input/output) REAL array, dimension (LDA,N)   
            On entry, the n by n general matrix to be reduced.   
            On exit, the upper triangle and the first subdiagonal of A   
            are overwritten with the upper Hessenberg matrix H, and the   
            elements below the first subdiagonal, with the array TAU,   
            represent the orthogonal matrix Q as a product of elementary   
            reflectors. See Further Details.   

    LDA     (input) INTEGER   
            The leading dimension of the array A.  LDA >= max(1,N).   

    TAU     (output) REAL array, dimension (N-1)   
            The scalar factors of the elementary reflectors (see Further   
            Details).   

    WORK    (workspace) REAL array, dimension (N)   

    INFO    (output) INTEGER   
            = 0:  successful exit.   
            < 0:  if INFO = -i, the i-th argument had an illegal value.   

    Further Details   
    ===============   

    The matrix Q is represented as a product of (ihi-ilo) elementary   
    reflectors   

       Q = H(ilo) H(ilo+1) . . . H(ihi-1).   

    Each H(i) has the form   

       H(i) = I - tau * v * v'   

    where tau is a real scalar, and v is a real vector with   
    v(1:i) = 0, v(i+1) = 1 and v(ihi+1:n) = 0; v(i+2:ihi) is stored on   
    exit in A(i+2:ihi,i), and tau in TAU(i).   

    The contents of A are illustrated by the following example, with   
    n = 7, ilo = 2 and ihi = 6:   

    on entry,                        on exit,   

    ( a   a   a   a   a   a   a )    (  a   a   h   h   h   h   a )   
    (     a   a   a   a   a   a )    (      a   h   h   h   h   a )   
    (     a   a   a   a   a   a )    (      h   h   h   h   h   h )   
    (     a   a   a   a   a   a )    (      v2  h   h   h   h   h )   
    (     a   a   a   a   a   a )    (      v2  v3  h   h   h   h )   
    (     a   a   a   a   a   a )    (      v2  v3  v4  h   h   h )   
    (                         a )    (                          a )   

    where a denotes an element of the original matrix A, h denotes a   
    modified element of the upper Hessenberg matrix H, and vi denotes an   
    element of the vector defining H(i).   

    =====================================================================   


       Test the input parameters   

       Parameter adjustments */
    /* Table of constant values */
    static integer c__1 = 1;
    
    /* System generated locals */
    integer a_dim1, a_offset, i__1, i__2, i__3;
    /* Local variables */
    static integer i__;
    extern /* Subroutine */ int slarf_(char *, integer *, integer *, real *, 
	    integer *, real *, real *, integer *, real *), xerbla_(
	    char *, integer *), slarfg_(integer *, real *, real *, 
	    integer *, real *);
    static real aii;
#define a_ref(a_1,a_2) a[(a_2)*a_dim1 + a_1]


    a_dim1 = *lda;
    a_offset = 1 + a_dim1 * 1;
    a -= a_offset;
    --tau;
    --work;

    /* Function Body */
    *info = 0;
    if (*n < 0) {
	*info = -1;
    } else if (*ilo < 1 || *ilo > max(1,*n)) {
	*info = -2;
    } else if (*ihi < min(*ilo,*n) || *ihi > *n) {
	*info = -3;
    } else if (*lda < max(1,*n)) {
	*info = -5;
    }
    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("SGEHD2", &i__1);
	return 0;
    }

    i__1 = *ihi - 1;
    for (i__ = *ilo; i__ <= i__1; ++i__) {

/*        Compute elementary reflector H(i) to annihilate A(i+2:ihi,i)   

   Computing MIN */
	i__2 = i__ + 2;
	i__3 = *ihi - i__;
	slarfg_(&i__3, &a_ref(i__ + 1, i__), &a_ref(min(i__2,*n), i__), &c__1,
		 &tau[i__]);
	aii = a_ref(i__ + 1, i__);
	a_ref(i__ + 1, i__) = 1.f;

/*        Apply H(i) to A(1:ihi,i+1:ihi) from the right */

	i__2 = *ihi - i__;
	slarf_("Right", ihi, &i__2, &a_ref(i__ + 1, i__), &c__1, &tau[i__], &
		a_ref(1, i__ + 1), lda, &work[1]);

/*        Apply H(i) to A(i+1:ihi,i+1:n) from the left */

	i__2 = *ihi - i__;
	i__3 = *n - i__;
	slarf_("Left", &i__2, &i__3, &a_ref(i__ + 1, i__), &c__1, &tau[i__], &
		a_ref(i__ + 1, i__ + 1), lda, &work[1]);

	a_ref(i__ + 1, i__) = aii;
/* L10: */
    }

    return 0;

/*     End of SGEHD2 */

} /* sgehd2_ */
Esempio n. 7
0
 int slaqp2_(int *m, int *n, int *offset, float *a, 
	 int *lda, int *jpvt, float *tau, float *vn1, float *vn2, float *
	work)
{
    /* System generated locals */
    int a_dim1, a_offset, i__1, i__2, i__3;
    float r__1, r__2;

    /* Builtin functions */
    double sqrt(double);

    /* Local variables */
    int i__, j, mn;
    float aii;
    int pvt;
    float temp, temp2;
    extern double snrm2_(int *, float *, int *);
    float tol3z;
    int offpi;
    extern  int slarf_(char *, int *, int *, float *, 
	    int *, float *, float *, int *, float *);
    int itemp;
    extern  int sswap_(int *, float *, int *, float *, 
	    int *);
    extern double slamch_(char *);
    extern int isamax_(int *, float *, int *);
    extern  int slarfp_(int *, float *, float *, int *, 
	    float *);


/*  -- LAPACK auxiliary routine (version 3.2) -- */
/*  -- LAPACK is a software package provided by Univ. of Tennessee,    -- */
/*  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
/*     November 2006 */

/*     .. Scalar Arguments .. */
/*     .. */
/*     .. Array Arguments .. */
/*     .. */

/*  Purpose */
/*  ======= */

/*  SLAQP2 computes a QR factorization with column pivoting of */
/*  the block A(OFFSET+1:M,1:N). */
/*  The block A(1:OFFSET,1:N) is accordingly pivoted, but not factorized. */

/*  Arguments */
/*  ========= */

/*  M       (input) INTEGER */
/*          The number of rows of the matrix A. M >= 0. */

/*  N       (input) INTEGER */
/*          The number of columns of the matrix A. N >= 0. */

/*  OFFSET  (input) INTEGER */
/*          The number of rows of the matrix A that must be pivoted */
/*          but no factorized. OFFSET >= 0. */

/*  A       (input/output) REAL array, dimension (LDA,N) */
/*          On entry, the M-by-N matrix A. */
/*          On exit, the upper triangle of block A(OFFSET+1:M,1:N) is */
/*          the triangular factor obtained; the elements in block */
/*          A(OFFSET+1:M,1:N) below the diagonal, together with the */
/*          array TAU, represent the orthogonal matrix Q as a product of */
/*          elementary reflectors. Block A(1:OFFSET,1:N) has been */
/*          accordingly pivoted, but no factorized. */

/*  LDA     (input) INTEGER */
/*          The leading dimension of the array A. LDA >= MAX(1,M). */

/*  JPVT    (input/output) INTEGER array, dimension (N) */
/*          On entry, if JPVT(i) .ne. 0, the i-th column of A is permuted */
/*          to the front of A*P (a leading column); if JPVT(i) = 0, */
/*          the i-th column of A is a free column. */
/*          On exit, if JPVT(i) = k, then the i-th column of A*P */
/*          was the k-th column of A. */

/*  TAU     (output) REAL array, dimension (MIN(M,N)) */
/*          The scalar factors of the elementary reflectors. */

/*  VN1     (input/output) REAL array, dimension (N) */
/*          The vector with the partial column norms. */

/*  VN2     (input/output) REAL array, dimension (N) */
/*          The vector with the exact column norms. */

/*  WORK    (workspace) REAL array, dimension (N) */

/*  Further Details */
/*  =============== */

/*  Based on contributions by */
/*    G. Quintana-Orti, Depto. de Informatica, Universidad Jaime I, Spain */
/*    X. Sun, Computer Science Dept., Duke University, USA */

/*  Partial column norm updating strategy modified by */
/*    Z. Drmac and Z. Bujanovic, Dept. of Mathematics, */
/*    University of Zagreb, Croatia. */
/*    June 2006. */
/*  For more details see LAPACK Working Note 176. */
/*  ===================================================================== */

/*     .. Parameters .. */
/*     .. */
/*     .. Local Scalars .. */
/*     .. */
/*     .. External Subroutines .. */
/*     .. */
/*     .. Intrinsic Functions .. */
/*     .. */
/*     .. External Functions .. */
/*     .. */
/*     .. Executable Statements .. */

    /* Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    --jpvt;
    --tau;
    --vn1;
    --vn2;
    --work;

    /* Function Body */
/* Computing MIN */
    i__1 = *m - *offset;
    mn = MIN(i__1,*n);
    tol3z = sqrt(slamch_("Epsilon"));

/*     Compute factorization. */

    i__1 = mn;
    for (i__ = 1; i__ <= i__1; ++i__) {

	offpi = *offset + i__;

/*        Determine ith pivot column and swap if necessary. */

	i__2 = *n - i__ + 1;
	pvt = i__ - 1 + isamax_(&i__2, &vn1[i__], &c__1);

	if (pvt != i__) {
	    sswap_(m, &a[pvt * a_dim1 + 1], &c__1, &a[i__ * a_dim1 + 1], &
		    c__1);
	    itemp = jpvt[pvt];
	    jpvt[pvt] = jpvt[i__];
	    jpvt[i__] = itemp;
	    vn1[pvt] = vn1[i__];
	    vn2[pvt] = vn2[i__];
	}

/*        Generate elementary reflector H(i). */

	if (offpi < *m) {
	    i__2 = *m - offpi + 1;
	    slarfp_(&i__2, &a[offpi + i__ * a_dim1], &a[offpi + 1 + i__ * 
		    a_dim1], &c__1, &tau[i__]);
	} else {
	    slarfp_(&c__1, &a[*m + i__ * a_dim1], &a[*m + i__ * a_dim1], &
		    c__1, &tau[i__]);
	}

	if (i__ < *n) {

/*           Apply H(i)' to A(offset+i:m,i+1:n) from the left. */

	    aii = a[offpi + i__ * a_dim1];
	    a[offpi + i__ * a_dim1] = 1.f;
	    i__2 = *m - offpi + 1;
	    i__3 = *n - i__;
	    slarf_("Left", &i__2, &i__3, &a[offpi + i__ * a_dim1], &c__1, &
		    tau[i__], &a[offpi + (i__ + 1) * a_dim1], lda, &work[1]);
	    a[offpi + i__ * a_dim1] = aii;
	}

/*        Update partial column norms. */

	i__2 = *n;
	for (j = i__ + 1; j <= i__2; ++j) {
	    if (vn1[j] != 0.f) {

/*              NOTE: The following 4 lines follow from the analysis in */
/*              Lapack Working Note 176. */

/* Computing 2nd power */
		r__2 = (r__1 = a[offpi + j * a_dim1], ABS(r__1)) / vn1[j];
		temp = 1.f - r__2 * r__2;
		temp = MAX(temp,0.f);
/* Computing 2nd power */
		r__1 = vn1[j] / vn2[j];
		temp2 = temp * (r__1 * r__1);
		if (temp2 <= tol3z) {
		    if (offpi < *m) {
			i__3 = *m - offpi;
			vn1[j] = snrm2_(&i__3, &a[offpi + 1 + j * a_dim1], &
				c__1);
			vn2[j] = vn1[j];
		    } else {
			vn1[j] = 0.f;
			vn2[j] = 0.f;
		    }
		} else {
		    vn1[j] *= sqrt(temp);
		}
	    }
/* L10: */
	}

/* L20: */
    }

    return 0;

/*     End of SLAQP2 */

} /* slaqp2_ */
Esempio n. 8
0
/* Subroutine */ int slaqp2_(integer *m, integer *n, integer *offset, real *a,
	 integer *lda, integer *jpvt, real *tau, real *vn1, real *vn2, real *
	work)
{
    /* System generated locals */
    integer a_dim1, a_offset, i__1, i__2, i__3;
    real r__1, r__2;

    /* Builtin functions */
    double sqrt(doublereal);

    /* Local variables */
    static integer i__, j, mn;
    static real aii;
    static integer pvt;
    static real temp, temp2;
    extern doublereal snrm2_(integer *, real *, integer *);
    static integer offpi;
    extern /* Subroutine */ int slarf_(char *, integer *, integer *, real *, 
	    integer *, real *, real *, integer *, real *, ftnlen);
    static integer itemp;
    extern /* Subroutine */ int sswap_(integer *, real *, integer *, real *, 
	    integer *), slarfg_(integer *, real *, real *, integer *, real *);
    extern integer isamax_(integer *, real *, integer *);


/*  -- LAPACK auxiliary routine (version 3.0) -- */
/*     Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd., */
/*     Courant Institute, Argonne National Lab, and Rice University */
/*     June 30, 1999 */

/*     .. Scalar Arguments .. */
/*     .. */
/*     .. Array Arguments .. */
/*     .. */

/*  Purpose */
/*  ======= */

/*  SLAQP2 computes a QR factorization with column pivoting of */
/*  the block A(OFFSET+1:M,1:N). */
/*  The block A(1:OFFSET,1:N) is accordingly pivoted, but not factorized. */

/*  Arguments */
/*  ========= */

/*  M       (input) INTEGER */
/*          The number of rows of the matrix A. M >= 0. */

/*  N       (input) INTEGER */
/*          The number of columns of the matrix A. N >= 0. */

/*  OFFSET  (input) INTEGER */
/*          The number of rows of the matrix A that must be pivoted */
/*          but no factorized. OFFSET >= 0. */

/*  A       (input/output) REAL array, dimension (LDA,N) */
/*          On entry, the M-by-N matrix A. */
/*          On exit, the upper triangle of block A(OFFSET+1:M,1:N) is */
/*          the triangular factor obtained; the elements in block */
/*          A(OFFSET+1:M,1:N) below the diagonal, together with the */
/*          array TAU, represent the orthogonal matrix Q as a product of */
/*          elementary reflectors. Block A(1:OFFSET,1:N) has been */
/*          accordingly pivoted, but no factorized. */

/*  LDA     (input) INTEGER */
/*          The leading dimension of the array A. LDA >= max(1,M). */

/*  JPVT    (input/output) INTEGER array, dimension (N) */
/*          On entry, if JPVT(i) .ne. 0, the i-th column of A is permuted */
/*          to the front of A*P (a leading column); if JPVT(i) = 0, */
/*          the i-th column of A is a free column. */
/*          On exit, if JPVT(i) = k, then the i-th column of A*P */
/*          was the k-th column of A. */

/*  TAU     (output) REAL array, dimension (min(M,N)) */
/*          The scalar factors of the elementary reflectors. */

/*  VN1     (input/output) REAL array, dimension (N) */
/*          The vector with the partial column norms. */

/*  VN2     (input/output) REAL array, dimension (N) */
/*          The vector with the exact column norms. */

/*  WORK    (workspace) REAL array, dimension (N) */

/*  Further Details */
/*  =============== */

/*  Based on contributions by */
/*    G. Quintana-Orti, Depto. de Informatica, Universidad Jaime I, Spain */
/*    X. Sun, Computer Science Dept., Duke University, USA */

/*  ===================================================================== */

/*     .. Parameters .. */
/*     .. */
/*     .. Local Scalars .. */
/*     .. */
/*     .. External Subroutines .. */
/*     .. */
/*     .. Intrinsic Functions .. */
/*     .. */
/*     .. External Functions .. */
/*     .. */
/*     .. Executable Statements .. */

    /* Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    --jpvt;
    --tau;
    --vn1;
    --vn2;
    --work;

    /* Function Body */
/* Computing MIN */
    i__1 = *m - *offset;
    mn = min(i__1,*n);

/*     Compute factorization. */

    i__1 = mn;
    for (i__ = 1; i__ <= i__1; ++i__) {

	offpi = *offset + i__;

/*        Determine ith pivot column and swap if necessary. */

	i__2 = *n - i__ + 1;
	pvt = i__ - 1 + isamax_(&i__2, &vn1[i__], &c__1);

	if (pvt != i__) {
	    sswap_(m, &a[pvt * a_dim1 + 1], &c__1, &a[i__ * a_dim1 + 1], &
		    c__1);
	    itemp = jpvt[pvt];
	    jpvt[pvt] = jpvt[i__];
	    jpvt[i__] = itemp;
	    vn1[pvt] = vn1[i__];
	    vn2[pvt] = vn2[i__];
	}

/*        Generate elementary reflector H(i). */

	if (offpi < *m) {
	    i__2 = *m - offpi + 1;
	    slarfg_(&i__2, &a[offpi + i__ * a_dim1], &a[offpi + 1 + i__ * 
		    a_dim1], &c__1, &tau[i__]);
	} else {
	    slarfg_(&c__1, &a[*m + i__ * a_dim1], &a[*m + i__ * a_dim1], &
		    c__1, &tau[i__]);
	}

	if (i__ < *n) {

/*           Apply H(i)' to A(offset+i:m,i+1:n) from the left. */

	    aii = a[offpi + i__ * a_dim1];
	    a[offpi + i__ * a_dim1] = 1.f;
	    i__2 = *m - offpi + 1;
	    i__3 = *n - i__;
	    slarf_("Left", &i__2, &i__3, &a[offpi + i__ * a_dim1], &c__1, &
		    tau[i__], &a[offpi + (i__ + 1) * a_dim1], lda, &work[1], (
		    ftnlen)4);
	    a[offpi + i__ * a_dim1] = aii;
	}

/*        Update partial column norms. */

	i__2 = *n;
	for (j = i__ + 1; j <= i__2; ++j) {
	    if (vn1[j] != 0.f) {
/* Computing 2nd power */
		r__2 = (r__1 = a[offpi + j * a_dim1], dabs(r__1)) / vn1[j];
		temp = 1.f - r__2 * r__2;
		temp = dmax(temp,0.f);
/* Computing 2nd power */
		r__1 = vn1[j] / vn2[j];
		temp2 = temp * .05f * (r__1 * r__1) + 1.f;
		if (temp2 == 1.f) {
		    if (offpi < *m) {
			i__3 = *m - offpi;
			vn1[j] = snrm2_(&i__3, &a[offpi + 1 + j * a_dim1], &
				c__1);
			vn2[j] = vn1[j];
		    } else {
			vn1[j] = 0.f;
			vn2[j] = 0.f;
		    }
		} else {
		    vn1[j] *= sqrt(temp);
		}
	    }
/* L10: */
	}

/* L20: */
    }

    return 0;

/*     End of SLAQP2 */

} /* slaqp2_ */
Esempio n. 9
0
/* Subroutine */ int sorgr2_(integer *m, integer *n, integer *k, real *a, 
	integer *lda, real *tau, real *work, integer *info)
{
/*  -- LAPACK routine (version 3.0) --   
       Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,   
       Courant Institute, Argonne National Lab, and Rice University   
       February 29, 1992   


    Purpose   
    =======   

    SORGR2 generates an m by n real matrix Q with orthonormal rows,   
    which is defined as the last m rows of a product of k elementary   
    reflectors of order n   

          Q  =  H(1) H(2) . . . H(k)   

    as returned by SGERQF.   

    Arguments   
    =========   

    M       (input) INTEGER   
            The number of rows of the matrix Q. M >= 0.   

    N       (input) INTEGER   
            The number of columns of the matrix Q. N >= M.   

    K       (input) INTEGER   
            The number of elementary reflectors whose product defines the   
            matrix Q. M >= K >= 0.   

    A       (input/output) REAL array, dimension (LDA,N)   
            On entry, the (m-k+i)-th row must contain the vector which   
            defines the elementary reflector H(i), for i = 1,2,...,k, as   
            returned by SGERQF in the last k rows of its array argument   
            A.   
            On exit, the m by n matrix Q.   

    LDA     (input) INTEGER   
            The first dimension of the array A. LDA >= max(1,M).   

    TAU     (input) REAL array, dimension (K)   
            TAU(i) must contain the scalar factor of the elementary   
            reflector H(i), as returned by SGERQF.   

    WORK    (workspace) REAL array, dimension (M)   

    INFO    (output) INTEGER   
            = 0: successful exit   
            < 0: if INFO = -i, the i-th argument has an illegal value   

    =====================================================================   


       Test the input arguments   

       Parameter adjustments */
    /* System generated locals */
    integer a_dim1, a_offset, i__1, i__2, i__3;
    real r__1;
    /* Local variables */
    static integer i__, j, l;
    extern /* Subroutine */ int sscal_(integer *, real *, real *, integer *), 
	    slarf_(char *, integer *, integer *, real *, integer *, real *, 
	    real *, integer *, real *);
    static integer ii;
    extern /* Subroutine */ int xerbla_(char *, integer *);
#define a_ref(a_1,a_2) a[(a_2)*a_dim1 + a_1]

    a_dim1 = *lda;
    a_offset = 1 + a_dim1 * 1;
    a -= a_offset;
    --tau;
    --work;

    /* Function Body */
    *info = 0;
    if (*m < 0) {
	*info = -1;
    } else if (*n < *m) {
	*info = -2;
    } else if (*k < 0 || *k > *m) {
	*info = -3;
    } else if (*lda < max(1,*m)) {
	*info = -5;
    }
    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("SORGR2", &i__1);
	return 0;
    }

/*     Quick return if possible */

    if (*m <= 0) {
	return 0;
    }

    if (*k < *m) {

/*        Initialise rows 1:m-k to rows of the unit matrix */

	i__1 = *n;
	for (j = 1; j <= i__1; ++j) {
	    i__2 = *m - *k;
	    for (l = 1; l <= i__2; ++l) {
		a_ref(l, j) = 0.f;
/* L10: */
	    }
	    if (j > *n - *m && j <= *n - *k) {
		a_ref(*m - *n + j, j) = 1.f;
	    }
/* L20: */
	}
    }

    i__1 = *k;
    for (i__ = 1; i__ <= i__1; ++i__) {
	ii = *m - *k + i__;

/*        Apply H(i) to A(1:m-k+i,1:n-k+i) from the right */

	a_ref(ii, *n - *m + ii) = 1.f;
	i__2 = ii - 1;
	i__3 = *n - *m + ii;
	slarf_("Right", &i__2, &i__3, &a_ref(ii, 1), lda, &tau[i__], &a[
		a_offset], lda, &work[1]);
	i__2 = *n - *m + ii - 1;
	r__1 = -tau[i__];
	sscal_(&i__2, &r__1, &a_ref(ii, 1), lda);
	a_ref(ii, *n - *m + ii) = 1.f - tau[i__];

/*        Set A(m-k+i,n-k+i+1:n) to zero */

	i__2 = *n;
	for (l = *n - *m + ii + 1; l <= i__2; ++l) {
	    a_ref(ii, l) = 0.f;
/* L30: */
	}
/* L40: */
    }
    return 0;

/*     End of SORGR2 */

} /* sorgr2_ */
Esempio n. 10
0
/* Subroutine */
int sorg2r_fla(integer *m, integer *n, integer *k, real *a, integer *lda, real *tau, real *work, integer *info)
{
    /* System generated locals */
    integer a_dim1, a_offset, i__1, i__2;
    real r__1;
    /* Local variables */
    integer i__, j, l;
    extern /* Subroutine */
    int sscal_(integer *, real *, real *, integer *), slarf_(char *, integer *, integer *, real *, integer *, real *, real *, integer *, real *), xerbla_(char *, integer *);
    /* -- LAPACK computational routine (version 3.4.2) -- */
    /* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
    /* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
    /* September 2012 */
    /* .. Scalar Arguments .. */
    /* .. */
    /* .. Array Arguments .. */
    /* .. */
    /* ===================================================================== */
    /* .. Parameters .. */
    /* .. */
    /* .. Local Scalars .. */
    /* .. */
    /* .. External Subroutines .. */
    /* .. */
    /* .. Intrinsic Functions .. */
    /* .. */
    /* .. Executable Statements .. */
    /* Test the input arguments */
    /* Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    --tau;
    --work;
    /* Function Body */
    *info = 0;
    if (*m < 0)
    {
        *info = -1;
    }
    else if (*n < 0 || *n > *m)
    {
        *info = -2;
    }
    else if (*k < 0 || *k > *n)
    {
        *info = -3;
    }
    else if (*lda < max(1,*m))
    {
        *info = -5;
    }
    if (*info != 0)
    {
        i__1 = -(*info);
        xerbla_("SORG2R", &i__1);
        return 0;
    }
    /* Quick return if possible */
    if (*n <= 0)
    {
        return 0;
    }
    /* Initialise columns k+1:n to columns of the unit matrix */
    i__1 = *n;
    for (j = *k + 1;
            j <= i__1;
            ++j)
    {
        i__2 = *m;
        for (l = 1;
                l <= i__2;
                ++l)
        {
            a[l + j * a_dim1] = 0.f;
            /* L10: */
        }
        a[j + j * a_dim1] = 1.f;
        /* L20: */
    }
    for (i__ = *k;
            i__ >= 1;
            --i__)
    {
        /* Apply H(i) to A(i:m,i:n) from the left */
        if (i__ < *n)
        {
            a[i__ + i__ * a_dim1] = 1.f;
            i__1 = *m - i__ + 1;
            i__2 = *n - i__;
            slarf_("Left", &i__1, &i__2, &a[i__ + i__ * a_dim1], &c__1, &tau[ i__], &a[i__ + (i__ + 1) * a_dim1], lda, &work[1]);
        }
        if (i__ < *m)
        {
            i__1 = *m - i__;
            r__1 = -tau[i__];
            sscal_(&i__1, &r__1, &a[i__ + 1 + i__ * a_dim1], &c__1);
        }
        a[i__ + i__ * a_dim1] = 1.f - tau[i__];
        /* Set A(1:i-1,i) to zero */
        i__1 = i__ - 1;
        for (l = 1;
                l <= i__1;
                ++l)
        {
            a[l + i__ * a_dim1] = 0.f;
            /* L30: */
        }
        /* L40: */
    }
    return 0;
    /* End of SORG2R */
}
Esempio n. 11
0
/* Subroutine */ int snapps_(integer *n, integer *kev, integer *np, real *
	shiftr, real *shifti, real *v, integer *ldv, real *h__, integer *ldh, 
	real *resid, real *q, integer *ldq, real *workl, real *workd)
{
    /* Initialized data */

    static logical first = TRUE_;

    /* System generated locals */
    integer h_dim1, h_offset, v_dim1, v_offset, q_dim1, q_offset, i__1, i__2, 
	    i__3, i__4;
    real r__1, r__2;

    /* Local variables */
    static real c__, f, g;
    static integer i__, j;
    static real r__, s, t, u[3], t0, t1, h11, h12, h21, h22, h32;
    static integer jj, ir, nr;
    static real tau, ulp, tst1;
    static integer iend;
    static real unfl, ovfl;
    static logical cconj;
    extern /* Subroutine */ int sscal_(integer *, real *, real *, integer *), 
	    slarf_(char *, integer *, integer *, real *, integer *, real *, 
	    real *, integer *, real *, ftnlen), sgemv_(char *, integer *, 
	    integer *, real *, real *, integer *, real *, integer *, real *, 
	    real *, integer *, ftnlen), scopy_(integer *, real *, integer *, 
	    real *, integer *), saxpy_(integer *, real *, real *, integer *, 
	    real *, integer *), ivout_(integer *, integer *, integer *, 
	    integer *, char *, ftnlen), smout_(integer *, integer *, integer *
	    , real *, integer *, integer *, char *, ftnlen), svout_(integer *,
	     integer *, real *, integer *, char *, ftnlen);
    extern doublereal slapy2_(real *, real *);
    extern /* Subroutine */ int slabad_(real *, real *);
    extern doublereal slamch_(char *, ftnlen);
    static real sigmai;
    extern /* Subroutine */ int second_(real *);
    static real sigmar;
    static integer istart, kplusp, msglvl;
    static real smlnum;
    extern /* Subroutine */ int slacpy_(char *, integer *, integer *, real *, 
	    integer *, real *, integer *, ftnlen), slarfg_(integer *, real *, 
	    real *, integer *, real *), slaset_(char *, integer *, integer *, 
	    real *, real *, real *, integer *, ftnlen), slartg_(real *, real *
	    , real *, real *, real *);
    extern doublereal slanhs_(char *, integer *, real *, integer *, real *, 
	    ftnlen);


/*     %----------------------------------------------------% */
/*     | Include files for debugging and timing information | */
/*     %----------------------------------------------------% */


/* \SCCS Information: @(#) */
/* FILE: debug.h   SID: 2.3   DATE OF SID: 11/16/95   RELEASE: 2 */

/*     %---------------------------------% */
/*     | See debug.doc for documentation | */
/*     %---------------------------------% */

/*     %------------------% */
/*     | Scalar Arguments | */
/*     %------------------% */

/*     %--------------------------------% */
/*     | See stat.doc for documentation | */
/*     %--------------------------------% */

/* \SCCS Information: @(#) */
/* FILE: stat.h   SID: 2.2   DATE OF SID: 11/16/95   RELEASE: 2 */



/*     %-----------------% */
/*     | Array Arguments | */
/*     %-----------------% */


/*     %------------% */
/*     | Parameters | */
/*     %------------% */


/*     %------------------------% */
/*     | Local Scalars & Arrays | */
/*     %------------------------% */


/*     %----------------------% */
/*     | External Subroutines | */
/*     %----------------------% */


/*     %--------------------% */
/*     | External Functions | */
/*     %--------------------% */


/*     %----------------------% */
/*     | Intrinsics Functions | */
/*     %----------------------% */


/*     %----------------% */
/*     | Data statments | */
/*     %----------------% */

    /* Parameter adjustments */
    --workd;
    --resid;
    --workl;
    --shifti;
    --shiftr;
    v_dim1 = *ldv;
    v_offset = 1 + v_dim1;
    v -= v_offset;
    h_dim1 = *ldh;
    h_offset = 1 + h_dim1;
    h__ -= h_offset;
    q_dim1 = *ldq;
    q_offset = 1 + q_dim1;
    q -= q_offset;

    /* Function Body */

/*     %-----------------------% */
/*     | Executable Statements | */
/*     %-----------------------% */

    if (first) {

/*        %-----------------------------------------------% */
/*        | Set machine-dependent constants for the       | */
/*        | stopping criterion. If norm(H) <= sqrt(OVFL), | */
/*        | overflow should not occur.                    | */
/*        | REFERENCE: LAPACK subroutine slahqr           | */
/*        %-----------------------------------------------% */

	unfl = slamch_("safe minimum", (ftnlen)12);
	ovfl = 1.f / unfl;
	slabad_(&unfl, &ovfl);
	ulp = slamch_("precision", (ftnlen)9);
	smlnum = unfl * (*n / ulp);
	first = FALSE_;
    }

/*     %-------------------------------% */
/*     | Initialize timing statistics  | */
/*     | & message level for debugging | */
/*     %-------------------------------% */

    second_(&t0);
    msglvl = debug_1.mnapps;
    kplusp = *kev + *np;

/*     %--------------------------------------------% */
/*     | Initialize Q to the identity to accumulate | */
/*     | the rotations and reflections              | */
/*     %--------------------------------------------% */

    slaset_("All", &kplusp, &kplusp, &c_b5, &c_b6, &q[q_offset], ldq, (ftnlen)
	    3);

/*     %----------------------------------------------% */
/*     | Quick return if there are no shifts to apply | */
/*     %----------------------------------------------% */

    if (*np == 0) {
	goto L9000;
    }

/*     %----------------------------------------------% */
/*     | Chase the bulge with the application of each | */
/*     | implicit shift. Each shift is applied to the | */
/*     | whole matrix including each block.           | */
/*     %----------------------------------------------% */

    cconj = FALSE_;
    i__1 = *np;
    for (jj = 1; jj <= i__1; ++jj) {
	sigmar = shiftr[jj];
	sigmai = shifti[jj];

	if (msglvl > 2) {
	    ivout_(&debug_1.logfil, &c__1, &jj, &debug_1.ndigit, "_napps: sh"
		    "ift number.", (ftnlen)21);
	    svout_(&debug_1.logfil, &c__1, &sigmar, &debug_1.ndigit, "_napps"
		    ": The real part of the shift ", (ftnlen)35);
	    svout_(&debug_1.logfil, &c__1, &sigmai, &debug_1.ndigit, "_napps"
		    ": The imaginary part of the shift ", (ftnlen)40);
	}

/*        %-------------------------------------------------% */
/*        | The following set of conditionals is necessary  | */
/*        | in order that complex conjugate pairs of shifts | */
/*        | are applied together or not at all.             | */
/*        %-------------------------------------------------% */

	if (cconj) {

/*           %-----------------------------------------% */
/*           | cconj = .true. means the previous shift | */
/*           | had non-zero imaginary part.            | */
/*           %-----------------------------------------% */

	    cconj = FALSE_;
	    goto L110;
	} else if (jj < *np && dabs(sigmai) > 0.f) {

/*           %------------------------------------% */
/*           | Start of a complex conjugate pair. | */
/*           %------------------------------------% */

	    cconj = TRUE_;
	} else if (jj == *np && dabs(sigmai) > 0.f) {

/*           %----------------------------------------------% */
/*           | The last shift has a nonzero imaginary part. | */
/*           | Don't apply it; thus the order of the        | */
/*           | compressed H is order KEV+1 since only np-1  | */
/*           | were applied.                                | */
/*           %----------------------------------------------% */

	    ++(*kev);
	    goto L110;
	}
	istart = 1;
L20:

/*        %--------------------------------------------------% */
/*        | if sigmai = 0 then                               | */
/*        |    Apply the jj-th shift ...                     | */
/*        | else                                             | */
/*        |    Apply the jj-th and (jj+1)-th together ...    | */
/*        |    (Note that jj < np at this point in the code) | */
/*        | end                                              | */
/*        | to the current block of H. The next do loop      | */
/*        | determines the current block ;                   | */
/*        %--------------------------------------------------% */

	i__2 = kplusp - 1;
	for (i__ = istart; i__ <= i__2; ++i__) {

/*           %----------------------------------------% */
/*           | Check for splitting and deflation. Use | */
/*           | a standard test as in the QR algorithm | */
/*           | REFERENCE: LAPACK subroutine slahqr    | */
/*           %----------------------------------------% */

	    tst1 = (r__1 = h__[i__ + i__ * h_dim1], dabs(r__1)) + (r__2 = h__[
		    i__ + 1 + (i__ + 1) * h_dim1], dabs(r__2));
	    if (tst1 == 0.f) {
		i__3 = kplusp - jj + 1;
		tst1 = slanhs_("1", &i__3, &h__[h_offset], ldh, &workl[1], (
			ftnlen)1);
	    }
/* Computing MAX */
	    r__2 = ulp * tst1;
	    if ((r__1 = h__[i__ + 1 + i__ * h_dim1], dabs(r__1)) <= dmax(r__2,
		    smlnum)) {
		if (msglvl > 0) {
		    ivout_(&debug_1.logfil, &c__1, &i__, &debug_1.ndigit, 
			    "_napps: matrix splitting at row/column no.", (
			    ftnlen)42);
		    ivout_(&debug_1.logfil, &c__1, &jj, &debug_1.ndigit, 
			    "_napps: matrix splitting with shift number.", (
			    ftnlen)43);
		    svout_(&debug_1.logfil, &c__1, &h__[i__ + 1 + i__ * 
			    h_dim1], &debug_1.ndigit, "_napps: off diagonal "
			    "element.", (ftnlen)29);
		}
		iend = i__;
		h__[i__ + 1 + i__ * h_dim1] = 0.f;
		goto L40;
	    }
/* L30: */
	}
	iend = kplusp;
L40:

	if (msglvl > 2) {
	    ivout_(&debug_1.logfil, &c__1, &istart, &debug_1.ndigit, "_napps"
		    ": Start of current block ", (ftnlen)31);
	    ivout_(&debug_1.logfil, &c__1, &iend, &debug_1.ndigit, "_napps: "
		    "End of current block ", (ftnlen)29);
	}

/*        %------------------------------------------------% */
/*        | No reason to apply a shift to block of order 1 | */
/*        %------------------------------------------------% */

	if (istart == iend) {
	    goto L100;
	}

/*        %------------------------------------------------------% */
/*        | If istart + 1 = iend then no reason to apply a       | */
/*        | complex conjugate pair of shifts on a 2 by 2 matrix. | */
/*        %------------------------------------------------------% */

	if (istart + 1 == iend && dabs(sigmai) > 0.f) {
	    goto L100;
	}

	h11 = h__[istart + istart * h_dim1];
	h21 = h__[istart + 1 + istart * h_dim1];
	if (dabs(sigmai) <= 0.f) {

/*           %---------------------------------------------% */
/*           | Real-valued shift ==> apply single shift QR | */
/*           %---------------------------------------------% */

	    f = h11 - sigmar;
	    g = h21;

	    i__2 = iend - 1;
	    for (i__ = istart; i__ <= i__2; ++i__) {

/*              %-----------------------------------------------------% */
/*              | Contruct the plane rotation G to zero out the bulge | */
/*              %-----------------------------------------------------% */

		slartg_(&f, &g, &c__, &s, &r__);
		if (i__ > istart) {

/*                 %-------------------------------------------% */
/*                 | The following ensures that h(1:iend-1,1), | */
/*                 | the first iend-2 off diagonal of elements | */
/*                 | H, remain non negative.                   | */
/*                 %-------------------------------------------% */

		    if (r__ < 0.f) {
			r__ = -r__;
			c__ = -c__;
			s = -s;
		    }
		    h__[i__ + (i__ - 1) * h_dim1] = r__;
		    h__[i__ + 1 + (i__ - 1) * h_dim1] = 0.f;
		}

/*              %---------------------------------------------% */
/*              | Apply rotation to the left of H;  H <- G'*H | */
/*              %---------------------------------------------% */

		i__3 = kplusp;
		for (j = i__; j <= i__3; ++j) {
		    t = c__ * h__[i__ + j * h_dim1] + s * h__[i__ + 1 + j * 
			    h_dim1];
		    h__[i__ + 1 + j * h_dim1] = -s * h__[i__ + j * h_dim1] + 
			    c__ * h__[i__ + 1 + j * h_dim1];
		    h__[i__ + j * h_dim1] = t;
/* L50: */
		}

/*              %---------------------------------------------% */
/*              | Apply rotation to the right of H;  H <- H*G | */
/*              %---------------------------------------------% */

/* Computing MIN */
		i__4 = i__ + 2;
		i__3 = min(i__4,iend);
		for (j = 1; j <= i__3; ++j) {
		    t = c__ * h__[j + i__ * h_dim1] + s * h__[j + (i__ + 1) * 
			    h_dim1];
		    h__[j + (i__ + 1) * h_dim1] = -s * h__[j + i__ * h_dim1] 
			    + c__ * h__[j + (i__ + 1) * h_dim1];
		    h__[j + i__ * h_dim1] = t;
/* L60: */
		}

/*              %----------------------------------------------------% */
/*              | Accumulate the rotation in the matrix Q;  Q <- Q*G | */
/*              %----------------------------------------------------% */

/* Computing MIN */
		i__4 = i__ + jj;
		i__3 = min(i__4,kplusp);
		for (j = 1; j <= i__3; ++j) {
		    t = c__ * q[j + i__ * q_dim1] + s * q[j + (i__ + 1) * 
			    q_dim1];
		    q[j + (i__ + 1) * q_dim1] = -s * q[j + i__ * q_dim1] + 
			    c__ * q[j + (i__ + 1) * q_dim1];
		    q[j + i__ * q_dim1] = t;
/* L70: */
		}

/*              %---------------------------% */
/*              | Prepare for next rotation | */
/*              %---------------------------% */

		if (i__ < iend - 1) {
		    f = h__[i__ + 1 + i__ * h_dim1];
		    g = h__[i__ + 2 + i__ * h_dim1];
		}
/* L80: */
	    }

/*           %-----------------------------------% */
/*           | Finished applying the real shift. | */
/*           %-----------------------------------% */

	} else {

/*           %----------------------------------------------------% */
/*           | Complex conjugate shifts ==> apply double shift QR | */
/*           %----------------------------------------------------% */

	    h12 = h__[istart + (istart + 1) * h_dim1];
	    h22 = h__[istart + 1 + (istart + 1) * h_dim1];
	    h32 = h__[istart + 2 + (istart + 1) * h_dim1];

/*           %---------------------------------------------------------% */
/*           | Compute 1st column of (H - shift*I)*(H - conj(shift)*I) | */
/*           %---------------------------------------------------------% */

	    s = sigmar * 2.f;
	    t = slapy2_(&sigmar, &sigmai);
	    u[0] = (h11 * (h11 - s) + t * t) / h21 + h12;
	    u[1] = h11 + h22 - s;
	    u[2] = h32;

	    i__2 = iend - 1;
	    for (i__ = istart; i__ <= i__2; ++i__) {

/* Computing MIN */
		i__3 = 3, i__4 = iend - i__ + 1;
		nr = min(i__3,i__4);

/*              %-----------------------------------------------------% */
/*              | Construct Householder reflector G to zero out u(1). | */
/*              | G is of the form I - tau*( 1 u )' * ( 1 u' ).       | */
/*              %-----------------------------------------------------% */

		slarfg_(&nr, u, &u[1], &c__1, &tau);

		if (i__ > istart) {
		    h__[i__ + (i__ - 1) * h_dim1] = u[0];
		    h__[i__ + 1 + (i__ - 1) * h_dim1] = 0.f;
		    if (i__ < iend - 1) {
			h__[i__ + 2 + (i__ - 1) * h_dim1] = 0.f;
		    }
		}
		u[0] = 1.f;

/*              %--------------------------------------% */
/*              | Apply the reflector to the left of H | */
/*              %--------------------------------------% */

		i__3 = kplusp - i__ + 1;
		slarf_("Left", &nr, &i__3, u, &c__1, &tau, &h__[i__ + i__ * 
			h_dim1], ldh, &workl[1], (ftnlen)4);

/*              %---------------------------------------% */
/*              | Apply the reflector to the right of H | */
/*              %---------------------------------------% */

/* Computing MIN */
		i__3 = i__ + 3;
		ir = min(i__3,iend);
		slarf_("Right", &ir, &nr, u, &c__1, &tau, &h__[i__ * h_dim1 + 
			1], ldh, &workl[1], (ftnlen)5);

/*              %-----------------------------------------------------% */
/*              | Accumulate the reflector in the matrix Q;  Q <- Q*G | */
/*              %-----------------------------------------------------% */

		slarf_("Right", &kplusp, &nr, u, &c__1, &tau, &q[i__ * q_dim1 
			+ 1], ldq, &workl[1], (ftnlen)5);

/*              %----------------------------% */
/*              | Prepare for next reflector | */
/*              %----------------------------% */

		if (i__ < iend - 1) {
		    u[0] = h__[i__ + 1 + i__ * h_dim1];
		    u[1] = h__[i__ + 2 + i__ * h_dim1];
		    if (i__ < iend - 2) {
			u[2] = h__[i__ + 3 + i__ * h_dim1];
		    }
		}

/* L90: */
	    }

/*           %--------------------------------------------% */
/*           | Finished applying a complex pair of shifts | */
/*           | to the current block                       | */
/*           %--------------------------------------------% */

	}

L100:

/*        %---------------------------------------------------------% */
/*        | Apply the same shift to the next block if there is any. | */
/*        %---------------------------------------------------------% */

	istart = iend + 1;
	if (iend < kplusp) {
	    goto L20;
	}

/*        %---------------------------------------------% */
/*        | Loop back to the top to get the next shift. | */
/*        %---------------------------------------------% */

L110:
	;
    }

/*     %--------------------------------------------------% */
/*     | Perform a similarity transformation that makes   | */
/*     | sure that H will have non negative sub diagonals | */
/*     %--------------------------------------------------% */

    i__1 = *kev;
    for (j = 1; j <= i__1; ++j) {
	if (h__[j + 1 + j * h_dim1] < 0.f) {
	    i__2 = kplusp - j + 1;
	    sscal_(&i__2, &c_b43, &h__[j + 1 + j * h_dim1], ldh);
/* Computing MIN */
	    i__3 = j + 2;
	    i__2 = min(i__3,kplusp);
	    sscal_(&i__2, &c_b43, &h__[(j + 1) * h_dim1 + 1], &c__1);
/* Computing MIN */
	    i__3 = j + *np + 1;
	    i__2 = min(i__3,kplusp);
	    sscal_(&i__2, &c_b43, &q[(j + 1) * q_dim1 + 1], &c__1);
	}
/* L120: */
    }

    i__1 = *kev;
    for (i__ = 1; i__ <= i__1; ++i__) {

/*        %--------------------------------------------% */
/*        | Final check for splitting and deflation.   | */
/*        | Use a standard test as in the QR algorithm | */
/*        | REFERENCE: LAPACK subroutine slahqr        | */
/*        %--------------------------------------------% */

	tst1 = (r__1 = h__[i__ + i__ * h_dim1], dabs(r__1)) + (r__2 = h__[i__ 
		+ 1 + (i__ + 1) * h_dim1], dabs(r__2));
	if (tst1 == 0.f) {
	    tst1 = slanhs_("1", kev, &h__[h_offset], ldh, &workl[1], (ftnlen)
		    1);
	}
/* Computing MAX */
	r__1 = ulp * tst1;
	if (h__[i__ + 1 + i__ * h_dim1] <= dmax(r__1,smlnum)) {
	    h__[i__ + 1 + i__ * h_dim1] = 0.f;
	}
/* L130: */
    }

/*     %-------------------------------------------------% */
/*     | Compute the (kev+1)-st column of (V*Q) and      | */
/*     | temporarily store the result in WORKD(N+1:2*N). | */
/*     | This is needed in the residual update since we  | */
/*     | cannot GUARANTEE that the corresponding entry   | */
/*     | of H would be zero as in exact arithmetic.      | */
/*     %-------------------------------------------------% */

    if (h__[*kev + 1 + *kev * h_dim1] > 0.f) {
	sgemv_("N", n, &kplusp, &c_b6, &v[v_offset], ldv, &q[(*kev + 1) * 
		q_dim1 + 1], &c__1, &c_b5, &workd[*n + 1], &c__1, (ftnlen)1);
    }

/*     %----------------------------------------------------------% */
/*     | Compute column 1 to kev of (V*Q) in backward order       | */
/*     | taking advantage of the upper Hessenberg structure of Q. | */
/*     %----------------------------------------------------------% */

    i__1 = *kev;
    for (i__ = 1; i__ <= i__1; ++i__) {
	i__2 = kplusp - i__ + 1;
	sgemv_("N", n, &i__2, &c_b6, &v[v_offset], ldv, &q[(*kev - i__ + 1) * 
		q_dim1 + 1], &c__1, &c_b5, &workd[1], &c__1, (ftnlen)1);
	scopy_(n, &workd[1], &c__1, &v[(kplusp - i__ + 1) * v_dim1 + 1], &
		c__1);
/* L140: */
    }

/*     %-------------------------------------------------% */
/*     |  Move v(:,kplusp-kev+1:kplusp) into v(:,1:kev). | */
/*     %-------------------------------------------------% */

    slacpy_("A", n, kev, &v[(kplusp - *kev + 1) * v_dim1 + 1], ldv, &v[
	    v_offset], ldv, (ftnlen)1);

/*     %--------------------------------------------------------------% */
/*     | Copy the (kev+1)-st column of (V*Q) in the appropriate place | */
/*     %--------------------------------------------------------------% */

    if (h__[*kev + 1 + *kev * h_dim1] > 0.f) {
	scopy_(n, &workd[*n + 1], &c__1, &v[(*kev + 1) * v_dim1 + 1], &c__1);
    }

/*     %-------------------------------------% */
/*     | Update the residual vector:         | */
/*     |    r <- sigmak*r + betak*v(:,kev+1) | */
/*     | where                               | */
/*     |    sigmak = (e_{kplusp}'*Q)*e_{kev} | */
/*     |    betak = e_{kev+1}'*H*e_{kev}     | */
/*     %-------------------------------------% */

    sscal_(n, &q[kplusp + *kev * q_dim1], &resid[1], &c__1);
    if (h__[*kev + 1 + *kev * h_dim1] > 0.f) {
	saxpy_(n, &h__[*kev + 1 + *kev * h_dim1], &v[(*kev + 1) * v_dim1 + 1],
		 &c__1, &resid[1], &c__1);
    }

    if (msglvl > 1) {
	svout_(&debug_1.logfil, &c__1, &q[kplusp + *kev * q_dim1], &
		debug_1.ndigit, "_napps: sigmak = (e_{kev+p}^T*Q)*e_{kev}", (
		ftnlen)40);
	svout_(&debug_1.logfil, &c__1, &h__[*kev + 1 + *kev * h_dim1], &
		debug_1.ndigit, "_napps: betak = e_{kev+1}^T*H*e_{kev}", (
		ftnlen)37);
	ivout_(&debug_1.logfil, &c__1, kev, &debug_1.ndigit, "_napps: Order "
		"of the final Hessenberg matrix ", (ftnlen)45);
	if (msglvl > 2) {
	    smout_(&debug_1.logfil, kev, kev, &h__[h_offset], ldh, &
		    debug_1.ndigit, "_napps: updated Hessenberg matrix H for"
		    " next iteration", (ftnlen)54);
	}

    }

L9000:
    second_(&t1);
    timing_1.tnapps += t1 - t0;

    return 0;

/*     %---------------% */
/*     | End of snapps | */
/*     %---------------% */

} /* snapps_ */
Esempio n. 12
0
/* Subroutine */ int sgeqpf_(integer *m, integer *n, real *a, integer *lda, 
	integer *jpvt, real *tau, real *work, integer *info)
{
    /* System generated locals */
    integer a_dim1, a_offset, i__1, i__2, i__3;
    real r__1, r__2;

    /* Builtin functions */
    double sqrt(doublereal);

    /* Local variables */
    integer i__, j, ma, mn;
    real aii;
    integer pvt;
    real temp, temp2;
    extern doublereal snrm2_(integer *, real *, integer *);
    real tol3z;
    extern /* Subroutine */ int slarf_(char *, integer *, integer *, real *, 
	    integer *, real *, real *, integer *, real *);
    integer itemp;
    extern /* Subroutine */ int sswap_(integer *, real *, integer *, real *, 
	    integer *), sgeqr2_(integer *, integer *, real *, integer *, real 
	    *, real *, integer *), sorm2r_(char *, char *, integer *, integer 
	    *, integer *, real *, integer *, real *, real *, integer *, real *
, integer *);
    extern doublereal slamch_(char *);
    extern /* Subroutine */ int xerbla_(char *, integer *), slarfg_(
	    integer *, real *, real *, integer *, real *);
    extern integer isamax_(integer *, real *, integer *);


/*  -- LAPACK deprecated driver routine (version 3.1) -- */
/*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/*     November 2006 */

/*     .. Scalar Arguments .. */
/*     .. */
/*     .. Array Arguments .. */
/*     .. */

/*  Purpose */
/*  ======= */

/*  This routine is deprecated and has been replaced by routine SGEQP3. */

/*  SGEQPF computes a QR factorization with column pivoting of a */
/*  real M-by-N matrix A: A*P = Q*R. */

/*  Arguments */
/*  ========= */

/*  M       (input) INTEGER */
/*          The number of rows of the matrix A. M >= 0. */

/*  N       (input) INTEGER */
/*          The number of columns of the matrix A. N >= 0 */

/*  A       (input/output) REAL array, dimension (LDA,N) */
/*          On entry, the M-by-N matrix A. */
/*          On exit, the upper triangle of the array contains the */
/*          min(M,N)-by-N upper triangular matrix R; the elements */
/*          below the diagonal, together with the array TAU, */
/*          represent the orthogonal matrix Q as a product of */
/*          min(m,n) elementary reflectors. */

/*  LDA     (input) INTEGER */
/*          The leading dimension of the array A. LDA >= max(1,M). */

/*  JPVT    (input/output) INTEGER array, dimension (N) */
/*          On entry, if JPVT(i) .ne. 0, the i-th column of A is permuted */
/*          to the front of A*P (a leading column); if JPVT(i) = 0, */
/*          the i-th column of A is a free column. */
/*          On exit, if JPVT(i) = k, then the i-th column of A*P */
/*          was the k-th column of A. */

/*  TAU     (output) REAL array, dimension (min(M,N)) */
/*          The scalar factors of the elementary reflectors. */

/*  WORK    (workspace) REAL array, dimension (3*N) */

/*  INFO    (output) INTEGER */
/*          = 0:  successful exit */
/*          < 0:  if INFO = -i, the i-th argument had an illegal value */

/*  Further Details */
/*  =============== */

/*  The matrix Q is represented as a product of elementary reflectors */

/*     Q = H(1) H(2) . . . H(n) */

/*  Each H(i) has the form */

/*     H = I - tau * v * v' */

/*  where tau is a real scalar, and v is a real vector with */
/*  v(1:i-1) = 0 and v(i) = 1; v(i+1:m) is stored on exit in A(i+1:m,i). */

/*  The matrix P is represented in jpvt as follows: If */
/*     jpvt(j) = i */
/*  then the jth column of P is the ith canonical unit vector. */

/*  Partial column norm updating strategy modified by */
/*    Z. Drmac and Z. Bujanovic, Dept. of Mathematics, */
/*    University of Zagreb, Croatia. */
/*    June 2006. */
/*  For more details see LAPACK Working Note 176. */

/*  ===================================================================== */

/*     .. Parameters .. */
/*     .. */
/*     .. Local Scalars .. */
/*     .. */
/*     .. External Subroutines .. */
/*     .. */
/*     .. Intrinsic Functions .. */
/*     .. */
/*     .. External Functions .. */
/*     .. */
/*     .. Executable Statements .. */

/*     Test the input arguments */

    /* Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    --jpvt;
    --tau;
    --work;

    /* Function Body */
    *info = 0;
    if (*m < 0) {
	*info = -1;
    } else if (*n < 0) {
	*info = -2;
    } else if (*lda < max(1,*m)) {
	*info = -4;
    }
    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("SGEQPF", &i__1);
	return 0;
    }

    mn = min(*m,*n);
    tol3z = sqrt(slamch_("Epsilon"));

/*     Move initial columns up front */

    itemp = 1;
    i__1 = *n;
    for (i__ = 1; i__ <= i__1; ++i__) {
	if (jpvt[i__] != 0) {
	    if (i__ != itemp) {
		sswap_(m, &a[i__ * a_dim1 + 1], &c__1, &a[itemp * a_dim1 + 1], 
			 &c__1);
		jpvt[i__] = jpvt[itemp];
		jpvt[itemp] = i__;
	    } else {
		jpvt[i__] = i__;
	    }
	    ++itemp;
	} else {
	    jpvt[i__] = i__;
	}
/* L10: */
    }
    --itemp;

/*     Compute the QR factorization and update remaining columns */

    if (itemp > 0) {
	ma = min(itemp,*m);
	sgeqr2_(m, &ma, &a[a_offset], lda, &tau[1], &work[1], info);
	if (ma < *n) {
	    i__1 = *n - ma;
	    sorm2r_("Left", "Transpose", m, &i__1, &ma, &a[a_offset], lda, &
		    tau[1], &a[(ma + 1) * a_dim1 + 1], lda, &work[1], info);
	}
    }

    if (itemp < mn) {

/*        Initialize partial column norms. The first n elements of */
/*        work store the exact column norms. */

	i__1 = *n;
	for (i__ = itemp + 1; i__ <= i__1; ++i__) {
	    i__2 = *m - itemp;
	    work[i__] = snrm2_(&i__2, &a[itemp + 1 + i__ * a_dim1], &c__1);
	    work[*n + i__] = work[i__];
/* L20: */
	}

/*        Compute factorization */

	i__1 = mn;
	for (i__ = itemp + 1; i__ <= i__1; ++i__) {

/*           Determine ith pivot column and swap if necessary */

	    i__2 = *n - i__ + 1;
	    pvt = i__ - 1 + isamax_(&i__2, &work[i__], &c__1);

	    if (pvt != i__) {
		sswap_(m, &a[pvt * a_dim1 + 1], &c__1, &a[i__ * a_dim1 + 1], &
			c__1);
		itemp = jpvt[pvt];
		jpvt[pvt] = jpvt[i__];
		jpvt[i__] = itemp;
		work[pvt] = work[i__];
		work[*n + pvt] = work[*n + i__];
	    }

/*           Generate elementary reflector H(i) */

	    if (i__ < *m) {
		i__2 = *m - i__ + 1;
		slarfg_(&i__2, &a[i__ + i__ * a_dim1], &a[i__ + 1 + i__ * 
			a_dim1], &c__1, &tau[i__]);
	    } else {
		slarfg_(&c__1, &a[*m + *m * a_dim1], &a[*m + *m * a_dim1], &
			c__1, &tau[*m]);
	    }

	    if (i__ < *n) {

/*              Apply H(i) to A(i:m,i+1:n) from the left */

		aii = a[i__ + i__ * a_dim1];
		a[i__ + i__ * a_dim1] = 1.f;
		i__2 = *m - i__ + 1;
		i__3 = *n - i__;
		slarf_("LEFT", &i__2, &i__3, &a[i__ + i__ * a_dim1], &c__1, &
			tau[i__], &a[i__ + (i__ + 1) * a_dim1], lda, &work[(*
			n << 1) + 1]);
		a[i__ + i__ * a_dim1] = aii;
	    }

/*           Update partial column norms */

	    i__2 = *n;
	    for (j = i__ + 1; j <= i__2; ++j) {
		if (work[j] != 0.f) {

/*                 NOTE: The following 4 lines follow from the analysis in */
/*                 Lapack Working Note 176. */

		    temp = (r__1 = a[i__ + j * a_dim1], dabs(r__1)) / work[j];
/* Computing MAX */
		    r__1 = 0.f, r__2 = (temp + 1.f) * (1.f - temp);
		    temp = dmax(r__1,r__2);
/* Computing 2nd power */
		    r__1 = work[j] / work[*n + j];
		    temp2 = temp * (r__1 * r__1);
		    if (temp2 <= tol3z) {
			if (*m - i__ > 0) {
			    i__3 = *m - i__;
			    work[j] = snrm2_(&i__3, &a[i__ + 1 + j * a_dim1], 
				    &c__1);
			    work[*n + j] = work[j];
			} else {
			    work[j] = 0.f;
			    work[*n + j] = 0.f;
			}
		    } else {
			work[j] *= sqrt(temp);
		    }
		}
/* L30: */
	    }

/* L40: */
	}
    }
    return 0;

/*     End of SGEQPF */

} /* sgeqpf_ */
Esempio n. 13
0
/* Subroutine */ int sgerq2_(integer *m, integer *n, real *a, integer *lda, 
	real *tau, real *work, integer *info)
{
/*  -- LAPACK routine (version 2.0) --   
       Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,   
       Courant Institute, Argonne National Lab, and Rice University   
       February 29, 1992   


    Purpose   
    =======   

    SGERQ2 computes an RQ factorization of a real m by n matrix A:   
    A = R * Q.   

    Arguments   
    =========   

    M       (input) INTEGER   
            The number of rows of the matrix A.  M >= 0.   

    N       (input) INTEGER   
            The number of columns of the matrix A.  N >= 0.   

    A       (input/output) REAL array, dimension (LDA,N)   
            On entry, the m by n matrix A.   
            On exit, if m <= n, the upper triangle of the subarray   
            A(1:m,n-m+1:n) contains the m by m upper triangular matrix R; 
  
            if m >= n, the elements on and above the (m-n)-th subdiagonal 
  
            contain the m by n upper trapezoidal matrix R; the remaining 
  
            elements, with the array TAU, represent the orthogonal matrix 
  
            Q as a product of elementary reflectors (see Further   
            Details).   

    LDA     (input) INTEGER   
            The leading dimension of the array A.  LDA >= max(1,M).   

    TAU     (output) REAL array, dimension (min(M,N))   
            The scalar factors of the elementary reflectors (see Further 
  
            Details).   

    WORK    (workspace) REAL array, dimension (M)   

    INFO    (output) INTEGER   
            = 0: successful exit   
            < 0: if INFO = -i, the i-th argument had an illegal value   

    Further Details   
    ===============   

    The matrix Q is represented as a product of elementary reflectors   

       Q = H(1) H(2) . . . H(k), where k = min(m,n).   

    Each H(i) has the form   

       H(i) = I - tau * v * v'   

    where tau is a real scalar, and v is a real vector with   
    v(n-k+i+1:n) = 0 and v(n-k+i) = 1; v(1:n-k+i-1) is stored on exit in 
  
    A(m-k+i,1:n-k+i-1), and tau in TAU(i).   

    ===================================================================== 
  


       Test the input arguments   

    
   Parameter adjustments   
       Function Body */
    /* System generated locals */
    integer a_dim1, a_offset, i__1, i__2;
    /* Local variables */
    static integer i, k;
    extern /* Subroutine */ int slarf_(char *, integer *, integer *, real *, 
	    integer *, real *, real *, integer *, real *), xerbla_(
	    char *, integer *), slarfg_(integer *, real *, real *, 
	    integer *, real *);
    static real aii;


#define TAU(I) tau[(I)-1]
#define WORK(I) work[(I)-1]

#define A(I,J) a[(I)-1 + ((J)-1)* ( *lda)]

    *info = 0;
    if (*m < 0) {
	*info = -1;
    } else if (*n < 0) {
	*info = -2;
    } else if (*lda < max(1,*m)) {
	*info = -4;
    }
    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("SGERQ2", &i__1);
	return 0;
    }

    k = min(*m,*n);

    for (i = k; i >= 1; --i) {

/*        Generate elementary reflector H(i) to annihilate   
          A(m-k+i,1:n-k+i-1) */

	i__1 = *n - k + i;
	slarfg_(&i__1, &A(*m-k+i,*n-k+i), &A(*m-k+i,1), lda, &TAU(i));

/*        Apply H(i) to A(1:m-k+i-1,1:n-k+i) from the right */

	aii = A(*m-k+i,*n-k+i);
	A(*m-k+i,*n-k+i) = 1.f;
	i__1 = *m - k + i - 1;
	i__2 = *n - k + i;
	slarf_("Right", &i__1, &i__2, &A(*m-k+i,1), lda, &TAU(i), &
		A(1,1), lda, &WORK(1));
	A(*m-k+i,*n-k+i) = aii;
/* L10: */
    }
    return 0;

/*     End of SGERQ2 */

} /* sgerq2_ */
Esempio n. 14
0
 int sorgr2_(int *m, int *n, int *k, float *a, 
	int *lda, float *tau, float *work, int *info)
{
    /* System generated locals */
    int a_dim1, a_offset, i__1, i__2, i__3;
    float r__1;

    /* Local variables */
    int i__, j, l, ii;
    extern  int sscal_(int *, float *, float *, int *), 
	    slarf_(char *, int *, int *, float *, int *, float *, 
	    float *, int *, float *), xerbla_(char *, int *);


/*  -- LAPACK routine (version 3.2) -- */
/*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/*     November 2006 */

/*     .. Scalar Arguments .. */
/*     .. */
/*     .. Array Arguments .. */
/*     .. */

/*  Purpose */
/*  ======= */

/*  SORGR2 generates an m by n float matrix Q with orthonormal rows, */
/*  which is defined as the last m rows of a product of k elementary */
/*  reflectors of order n */

/*        Q  =  H(1) H(2) . . . H(k) */

/*  as returned by SGERQF. */

/*  Arguments */
/*  ========= */

/*  M       (input) INTEGER */
/*          The number of rows of the matrix Q. M >= 0. */

/*  N       (input) INTEGER */
/*          The number of columns of the matrix Q. N >= M. */

/*  K       (input) INTEGER */
/*          The number of elementary reflectors whose product defines the */
/*          matrix Q. M >= K >= 0. */

/*  A       (input/output) REAL array, dimension (LDA,N) */
/*          On entry, the (m-k+i)-th row must contain the vector which */
/*          defines the elementary reflector H(i), for i = 1,2,...,k, as */
/*          returned by SGERQF in the last k rows of its array argument */
/*          A. */
/*          On exit, the m by n matrix Q. */

/*  LDA     (input) INTEGER */
/*          The first dimension of the array A. LDA >= MAX(1,M). */

/*  TAU     (input) REAL array, dimension (K) */
/*          TAU(i) must contain the scalar factor of the elementary */
/*          reflector H(i), as returned by SGERQF. */

/*  WORK    (workspace) REAL array, dimension (M) */

/*  INFO    (output) INTEGER */
/*          = 0: successful exit */
/*          < 0: if INFO = -i, the i-th argument has an illegal value */

/*  ===================================================================== */

/*     .. Parameters .. */
/*     .. */
/*     .. Local Scalars .. */
/*     .. */
/*     .. External Subroutines .. */
/*     .. */
/*     .. Intrinsic Functions .. */
/*     .. */
/*     .. Executable Statements .. */

/*     Test the input arguments */

    /* Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    --tau;
    --work;

    /* Function Body */
    *info = 0;
    if (*m < 0) {
	*info = -1;
    } else if (*n < *m) {
	*info = -2;
    } else if (*k < 0 || *k > *m) {
	*info = -3;
    } else if (*lda < MAX(1,*m)) {
	*info = -5;
    }
    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("SORGR2", &i__1);
	return 0;
    }

/*     Quick return if possible */

    if (*m <= 0) {
	return 0;
    }

    if (*k < *m) {

/*        Initialise rows 1:m-k to rows of the unit matrix */

	i__1 = *n;
	for (j = 1; j <= i__1; ++j) {
	    i__2 = *m - *k;
	    for (l = 1; l <= i__2; ++l) {
		a[l + j * a_dim1] = 0.f;
/* L10: */
	    }
	    if (j > *n - *m && j <= *n - *k) {
		a[*m - *n + j + j * a_dim1] = 1.f;
	    }
/* L20: */
	}
    }

    i__1 = *k;
    for (i__ = 1; i__ <= i__1; ++i__) {
	ii = *m - *k + i__;

/*        Apply H(i) to A(1:m-k+i,1:n-k+i) from the right */

	a[ii + (*n - *m + ii) * a_dim1] = 1.f;
	i__2 = ii - 1;
	i__3 = *n - *m + ii;
	slarf_("Right", &i__2, &i__3, &a[ii + a_dim1], lda, &tau[i__], &a[
		a_offset], lda, &work[1]);
	i__2 = *n - *m + ii - 1;
	r__1 = -tau[i__];
	sscal_(&i__2, &r__1, &a[ii + a_dim1], lda);
	a[ii + (*n - *m + ii) * a_dim1] = 1.f - tau[i__];

/*        Set A(m-k+i,n-k+i+1:n) to zero */

	i__2 = *n;
	for (l = *n - *m + ii + 1; l <= i__2; ++l) {
	    a[ii + l * a_dim1] = 0.f;
/* L30: */
	}
/* L40: */
    }
    return 0;

/*     End of SORGR2 */

} /* sorgr2_ */
Esempio n. 15
0
/* Subroutine */ int sgehd2_(integer *n, integer *ilo, integer *ihi, real *a, 
	integer *lda, real *tau, real *work, integer *info)
{
    /* System generated locals */
    integer a_dim1, a_offset, i__1, i__2, i__3;

    /* Local variables */
    integer i__;
    real aii;
    extern /* Subroutine */ int slarf_(char *, integer *, integer *, real *, 
	    integer *, real *, real *, integer *, real *), xerbla_(
	    char *, integer *), slarfg_(integer *, real *, real *, 
	    integer *, real *);


/*  -- LAPACK routine (version 3.2) -- */
/*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/*     November 2006 */

/*     .. Scalar Arguments .. */
/*     .. */
/*     .. Array Arguments .. */
/*     .. */

/*  Purpose */
/*  ======= */

/*  SGEHD2 reduces a real general matrix A to upper Hessenberg form H by */
/*  an orthogonal similarity transformation:  Q' * A * Q = H . */

/*  Arguments */
/*  ========= */

/*  N       (input) INTEGER */
/*          The order of the matrix A.  N >= 0. */

/*  ILO     (input) INTEGER */
/*  IHI     (input) INTEGER */
/*          It is assumed that A is already upper triangular in rows */
/*          and columns 1:ILO-1 and IHI+1:N. ILO and IHI are normally */
/*          set by a previous call to SGEBAL; otherwise they should be */
/*          set to 1 and N respectively. See Further Details. */
/*          1 <= ILO <= IHI <= max(1,N). */

/*  A       (input/output) REAL array, dimension (LDA,N) */
/*          On entry, the n by n general matrix to be reduced. */
/*          On exit, the upper triangle and the first subdiagonal of A */
/*          are overwritten with the upper Hessenberg matrix H, and the */
/*          elements below the first subdiagonal, with the array TAU, */
/*          represent the orthogonal matrix Q as a product of elementary */
/*          reflectors. See Further Details. */

/*  LDA     (input) INTEGER */
/*          The leading dimension of the array A.  LDA >= max(1,N). */

/*  TAU     (output) REAL array, dimension (N-1) */
/*          The scalar factors of the elementary reflectors (see Further */
/*          Details). */

/*  WORK    (workspace) REAL array, dimension (N) */

/*  INFO    (output) INTEGER */
/*          = 0:  successful exit. */
/*          < 0:  if INFO = -i, the i-th argument had an illegal value. */

/*  Further Details */
/*  =============== */

/*  The matrix Q is represented as a product of (ihi-ilo) elementary */
/*  reflectors */

/*     Q = H(ilo) H(ilo+1) . . . H(ihi-1). */

/*  Each H(i) has the form */

/*     H(i) = I - tau * v * v' */

/*  where tau is a real scalar, and v is a real vector with */
/*  v(1:i) = 0, v(i+1) = 1 and v(ihi+1:n) = 0; v(i+2:ihi) is stored on */
/*  exit in A(i+2:ihi,i), and tau in TAU(i). */

/*  The contents of A are illustrated by the following example, with */
/*  n = 7, ilo = 2 and ihi = 6: */

/*  on entry,                        on exit, */

/*  ( a   a   a   a   a   a   a )    (  a   a   h   h   h   h   a ) */
/*  (     a   a   a   a   a   a )    (      a   h   h   h   h   a ) */
/*  (     a   a   a   a   a   a )    (      h   h   h   h   h   h ) */
/*  (     a   a   a   a   a   a )    (      v2  h   h   h   h   h ) */
/*  (     a   a   a   a   a   a )    (      v2  v3  h   h   h   h ) */
/*  (     a   a   a   a   a   a )    (      v2  v3  v4  h   h   h ) */
/*  (                         a )    (                          a ) */

/*  where a denotes an element of the original matrix A, h denotes a */
/*  modified element of the upper Hessenberg matrix H, and vi denotes an */
/*  element of the vector defining H(i). */

/*  ===================================================================== */

/*     .. Parameters .. */
/*     .. */
/*     .. Local Scalars .. */
/*     .. */
/*     .. External Subroutines .. */
/*     .. */
/*     .. Intrinsic Functions .. */
/*     .. */
/*     .. Executable Statements .. */

/*     Test the input parameters */

    /* Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    --tau;
    --work;

    /* Function Body */
    *info = 0;
    if (*n < 0) {
	*info = -1;
    } else if (*ilo < 1 || *ilo > max(1,*n)) {
	*info = -2;
    } else if (*ihi < min(*ilo,*n) || *ihi > *n) {
	*info = -3;
    } else if (*lda < max(1,*n)) {
	*info = -5;
    }
    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("SGEHD2", &i__1);
	return 0;
    }

    i__1 = *ihi - 1;
    for (i__ = *ilo; i__ <= i__1; ++i__) {

/*        Compute elementary reflector H(i) to annihilate A(i+2:ihi,i) */

	i__2 = *ihi - i__;
/* Computing MIN */
	i__3 = i__ + 2;
	slarfg_(&i__2, &a[i__ + 1 + i__ * a_dim1], &a[min(i__3, *n)+ i__ * 
		a_dim1], &c__1, &tau[i__]);
	aii = a[i__ + 1 + i__ * a_dim1];
	a[i__ + 1 + i__ * a_dim1] = 1.f;

/*        Apply H(i) to A(1:ihi,i+1:ihi) from the right */

	i__2 = *ihi - i__;
	slarf_("Right", ihi, &i__2, &a[i__ + 1 + i__ * a_dim1], &c__1, &tau[
		i__], &a[(i__ + 1) * a_dim1 + 1], lda, &work[1]);

/*        Apply H(i) to A(i+1:ihi,i+1:n) from the left */

	i__2 = *ihi - i__;
	i__3 = *n - i__;
	slarf_("Left", &i__2, &i__3, &a[i__ + 1 + i__ * a_dim1], &c__1, &tau[
		i__], &a[i__ + 1 + (i__ + 1) * a_dim1], lda, &work[1]);

	a[i__ + 1 + i__ * a_dim1] = aii;
/* L10: */
    }

    return 0;

/*     End of SGEHD2 */

} /* sgehd2_ */
Esempio n. 16
0
/* Subroutine */ int sqrt15_(integer *scale, integer *rksel, integer *m,
                             integer *n, integer *nrhs, real *a, integer *lda, real *b, integer *
                             ldb, real *s, integer *rank, real *norma, real *normb, integer *iseed,
                             real *work, integer *lwork)
{
    /* System generated locals */
    integer a_dim1, a_offset, b_dim1, b_offset, i__1, i__2;
    real r__1;

    /* Local variables */
    static integer info;
    static real temp;
    extern doublereal snrm2_(integer *, real *, integer *);
    static integer j;
    extern /* Subroutine */ int sscal_(integer *, real *, real *, integer *),
           slarf_(char *, integer *, integer *, real *, integer *, real *,
                  real *, integer *, real *), sgemm_(char *, char *,
                          integer *, integer *, integer *, real *, real *, integer *, real *
                          , integer *, real *, real *, integer *);
    extern doublereal sasum_(integer *, real *, integer *);
    static real dummy[1];
    static integer mn;
    extern doublereal slamch_(char *), slange_(char *, integer *,
            integer *, real *, integer *, real *);
    extern /* Subroutine */ int xerbla_(char *, integer *);
    static real bignum;
    extern /* Subroutine */ int slascl_(char *, integer *, integer *, real *,
                                        real *, integer *, integer *, real *, integer *, integer *);
    extern doublereal slarnd_(integer *, integer *);
    extern /* Subroutine */ int slaord_(char *, integer *, real *, integer *), slaset_(char *, integer *, integer *, real *, real *,
            real *, integer *), slaror_(char *, char *, integer *,
                                        integer *, real *, integer *, integer *, real *, integer *), slarnv_(integer *, integer *, integer *, real *);
    static real smlnum, eps;


#define a_ref(a_1,a_2) a[(a_2)*a_dim1 + a_1]


    /*  -- LAPACK test routine (version 3.0) --
           Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,
           Courant Institute, Argonne National Lab, and Rice University
           September 30, 1994


        Purpose
        =======

        SQRT15 generates a matrix with full or deficient rank and of various
        norms.

        Arguments
        =========

        SCALE   (input) INTEGER
                SCALE = 1: normally scaled matrix
                SCALE = 2: matrix scaled up
                SCALE = 3: matrix scaled down

        RKSEL   (input) INTEGER
                RKSEL = 1: full rank matrix
                RKSEL = 2: rank-deficient matrix

        M       (input) INTEGER
                The number of rows of the matrix A.

        N       (input) INTEGER
                The number of columns of A.

        NRHS    (input) INTEGER
                The number of columns of B.

        A       (output) REAL array, dimension (LDA,N)
                The M-by-N matrix A.

        LDA     (input) INTEGER
                The leading dimension of the array A.

        B       (output) REAL array, dimension (LDB, NRHS)
                A matrix that is in the range space of matrix A.

        LDB     (input) INTEGER
                The leading dimension of the array B.

        S       (output) REAL array, dimension MIN(M,N)
                Singular values of A.

        RANK    (output) INTEGER
                number of nonzero singular values of A.

        NORMA   (output) REAL
                one-norm of A.

        NORMB   (output) REAL
                one-norm of B.

        ISEED   (input/output) integer array, dimension (4)
                seed for random number generator.

        WORK    (workspace) REAL array, dimension (LWORK)

        LWORK   (input) INTEGER
                length of work space required.
                LWORK >= MAX(M+MIN(M,N),NRHS*MIN(M,N),2*N+M)

        =====================================================================


           Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1 * 1;
    a -= a_offset;
    b_dim1 = *ldb;
    b_offset = 1 + b_dim1 * 1;
    b -= b_offset;
    --s;
    --iseed;
    --work;

    /* Function Body */
    mn = min(*m,*n);
    /* Computing MAX */
    i__1 = *m + mn, i__2 = mn * *nrhs, i__1 = max(i__1,i__2), i__2 = (*n << 1)
                           + *m;
    if (*lwork < max(i__1,i__2)) {
        xerbla_("SQRT15", &c__16);
        return 0;
    }

    smlnum = slamch_("Safe minimum");
    bignum = 1.f / smlnum;
    eps = slamch_("Epsilon");
    smlnum = smlnum / eps / eps;
    bignum = 1.f / smlnum;

    /*     Determine rank and (unscaled) singular values */

    if (*rksel == 1) {
        *rank = mn;
    } else if (*rksel == 2) {
        *rank = mn * 3 / 4;
        i__1 = mn;
        for (j = *rank + 1; j <= i__1; ++j) {
            s[j] = 0.f;
            /* L10: */
        }
    } else {
        xerbla_("SQRT15", &c__2);
    }

    if (*rank > 0) {

        /*        Nontrivial case */

        s[1] = 1.f;
        i__1 = *rank;
        for (j = 2; j <= i__1; ++j) {
L20:
            temp = slarnd_(&c__1, &iseed[1]);
            if (temp > .1f) {
                s[j] = dabs(temp);
            } else {
                goto L20;
            }
            /* L30: */
        }
        slaord_("Decreasing", rank, &s[1], &c__1);

        /*        Generate 'rank' columns of a random orthogonal matrix in A */

        slarnv_(&c__2, &iseed[1], m, &work[1]);
        r__1 = 1.f / snrm2_(m, &work[1], &c__1);
        sscal_(m, &r__1, &work[1], &c__1);
        slaset_("Full", m, rank, &c_b18, &c_b19, &a[a_offset], lda)
        ;
        slarf_("Left", m, rank, &work[1], &c__1, &c_b22, &a[a_offset], lda, &
               work[*m + 1]);

        /*        workspace used: m+mn

                  Generate consistent rhs in the range space of A */

        i__1 = *rank * *nrhs;
        slarnv_(&c__2, &iseed[1], &i__1, &work[1]);
        sgemm_("No transpose", "No transpose", m, nrhs, rank, &c_b19, &a[
                   a_offset], lda, &work[1], rank, &c_b18, &b[b_offset], ldb);

        /*        work space used: <= mn *nrhs

                  generate (unscaled) matrix A */

        i__1 = *rank;
        for (j = 1; j <= i__1; ++j) {
            sscal_(m, &s[j], &a_ref(1, j), &c__1);
            /* L40: */
        }
        if (*rank < *n) {
            i__1 = *n - *rank;
            slaset_("Full", m, &i__1, &c_b18, &c_b18, &a_ref(1, *rank + 1),
                    lda);
        }
        slaror_("Right", "No initialization", m, n, &a[a_offset], lda, &iseed[
                    1], &work[1], &info);

    } else {

        /*        work space used 2*n+m

                  Generate null matrix and rhs */

        i__1 = mn;
        for (j = 1; j <= i__1; ++j) {
            s[j] = 0.f;
            /* L50: */
        }
        slaset_("Full", m, n, &c_b18, &c_b18, &a[a_offset], lda);
        slaset_("Full", m, nrhs, &c_b18, &c_b18, &b[b_offset], ldb)
        ;

    }

    /*     Scale the matrix */

    if (*scale != 1) {
        *norma = slange_("Max", m, n, &a[a_offset], lda, dummy);
        if (*norma != 0.f) {
            if (*scale == 2) {

                /*              matrix scaled up */

                slascl_("General", &c__0, &c__0, norma, &bignum, m, n, &a[
                            a_offset], lda, &info);
                slascl_("General", &c__0, &c__0, norma, &bignum, &mn, &c__1, &
                        s[1], &mn, &info);
                slascl_("General", &c__0, &c__0, norma, &bignum, m, nrhs, &b[
                            b_offset], ldb, &info);
            } else if (*scale == 3) {

                /*              matrix scaled down */

                slascl_("General", &c__0, &c__0, norma, &smlnum, m, n, &a[
                            a_offset], lda, &info);
                slascl_("General", &c__0, &c__0, norma, &smlnum, &mn, &c__1, &
                        s[1], &mn, &info);
                slascl_("General", &c__0, &c__0, norma, &smlnum, m, nrhs, &b[
                            b_offset], ldb, &info);
            } else {
                xerbla_("SQRT15", &c__1);
                return 0;
            }
        }
    }

    *norma = sasum_(&mn, &s[1], &c__1);
    *normb = slange_("One-norm", m, nrhs, &b[b_offset], ldb, dummy)
             ;

    return 0;

    /*     End of SQRT15 */

} /* sqrt15_ */
Esempio n. 17
0
/* Subroutine */ int slarfx_(char *side, integer *m, integer *n, real *v, 
	real *tau, real *c__, integer *ldc, real *work)
{
    /* System generated locals */
    integer c_dim1, c_offset, i__1;

    /* Local variables */
    integer j;
    real t1, t2, t3, t4, t5, t6, t7, t8, t9, v1, v2, v3, v4, v5, v6, v7, v8, 
	    v9, t10, v10, sum;
    extern logical lsame_(char *, char *);
    extern /* Subroutine */ int slarf_(char *, integer *, integer *, real *, 
	    integer *, real *, real *, integer *, real *);


/*  -- LAPACK auxiliary routine (version 3.2) -- */
/*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/*     November 2006 */

/*     .. Scalar Arguments .. */
/*     .. */
/*     .. Array Arguments .. */
/*     .. */

/*  Purpose */
/*  ======= */

/*  SLARFX applies a real elementary reflector H to a real m by n */
/*  matrix C, from either the left or the right. H is represented in the */
/*  form */

/*        H = I - tau * v * v' */

/*  where tau is a real scalar and v is a real vector. */

/*  If tau = 0, then H is taken to be the unit matrix */

/*  This version uses inline code if H has order < 11. */

/*  Arguments */
/*  ========= */

/*  SIDE    (input) CHARACTER*1 */
/*          = 'L': form  H * C */
/*          = 'R': form  C * H */

/*  M       (input) INTEGER */
/*          The number of rows of the matrix C. */

/*  N       (input) INTEGER */
/*          The number of columns of the matrix C. */

/*  V       (input) REAL array, dimension (M) if SIDE = 'L' */
/*                                     or (N) if SIDE = 'R' */
/*          The vector v in the representation of H. */

/*  TAU     (input) REAL */
/*          The value tau in the representation of H. */

/*  C       (input/output) REAL array, dimension (LDC,N) */
/*          On entry, the m by n matrix C. */
/*          On exit, C is overwritten by the matrix H * C if SIDE = 'L', */
/*          or C * H if SIDE = 'R'. */

/*  LDC     (input) INTEGER */
/*          The leading dimension of the array C. LDA >= (1,M). */

/*  WORK    (workspace) REAL array, dimension */
/*                      (N) if SIDE = 'L' */
/*                      or (M) if SIDE = 'R' */
/*          WORK is not referenced if H has order < 11. */

/*  ===================================================================== */

/*     .. Parameters .. */
/*     .. */
/*     .. Local Scalars .. */
/*     .. */
/*     .. External Functions .. */
/*     .. */
/*     .. External Subroutines .. */
/*     .. */
/*     .. Executable Statements .. */

    /* Parameter adjustments */
    --v;
    c_dim1 = *ldc;
    c_offset = 1 + c_dim1;
    c__ -= c_offset;
    --work;

    /* Function Body */
    if (*tau == 0.f) {
	return 0;
    }
    if (lsame_(side, "L")) {

/*        Form  H * C, where H has order m. */

	switch (*m) {
	    case 1:  goto L10;
	    case 2:  goto L30;
	    case 3:  goto L50;
	    case 4:  goto L70;
	    case 5:  goto L90;
	    case 6:  goto L110;
	    case 7:  goto L130;
	    case 8:  goto L150;
	    case 9:  goto L170;
	    case 10:  goto L190;
	}

/*        Code for general M */

	slarf_(side, m, n, &v[1], &c__1, tau, &c__[c_offset], ldc, &work[1]);
	goto L410;
L10:

/*        Special code for 1 x 1 Householder */

	t1 = 1.f - *tau * v[1] * v[1];
	i__1 = *n;
	for (j = 1; j <= i__1; ++j) {
	    c__[j * c_dim1 + 1] = t1 * c__[j * c_dim1 + 1];
/* L20: */
	}
	goto L410;
L30:

/*        Special code for 2 x 2 Householder */

	v1 = v[1];
	t1 = *tau * v1;
	v2 = v[2];
	t2 = *tau * v2;
	i__1 = *n;
	for (j = 1; j <= i__1; ++j) {
	    sum = v1 * c__[j * c_dim1 + 1] + v2 * c__[j * c_dim1 + 2];
	    c__[j * c_dim1 + 1] -= sum * t1;
	    c__[j * c_dim1 + 2] -= sum * t2;
/* L40: */
	}
	goto L410;
L50:

/*        Special code for 3 x 3 Householder */

	v1 = v[1];
	t1 = *tau * v1;
	v2 = v[2];
	t2 = *tau * v2;
	v3 = v[3];
	t3 = *tau * v3;
	i__1 = *n;
	for (j = 1; j <= i__1; ++j) {
	    sum = v1 * c__[j * c_dim1 + 1] + v2 * c__[j * c_dim1 + 2] + v3 * 
		    c__[j * c_dim1 + 3];
	    c__[j * c_dim1 + 1] -= sum * t1;
	    c__[j * c_dim1 + 2] -= sum * t2;
	    c__[j * c_dim1 + 3] -= sum * t3;
/* L60: */
	}
	goto L410;
L70:

/*        Special code for 4 x 4 Householder */

	v1 = v[1];
	t1 = *tau * v1;
	v2 = v[2];
	t2 = *tau * v2;
	v3 = v[3];
	t3 = *tau * v3;
	v4 = v[4];
	t4 = *tau * v4;
	i__1 = *n;
	for (j = 1; j <= i__1; ++j) {
	    sum = v1 * c__[j * c_dim1 + 1] + v2 * c__[j * c_dim1 + 2] + v3 * 
		    c__[j * c_dim1 + 3] + v4 * c__[j * c_dim1 + 4];
	    c__[j * c_dim1 + 1] -= sum * t1;
	    c__[j * c_dim1 + 2] -= sum * t2;
	    c__[j * c_dim1 + 3] -= sum * t3;
	    c__[j * c_dim1 + 4] -= sum * t4;
/* L80: */
	}
	goto L410;
L90:

/*        Special code for 5 x 5 Householder */

	v1 = v[1];
	t1 = *tau * v1;
	v2 = v[2];
	t2 = *tau * v2;
	v3 = v[3];
	t3 = *tau * v3;
	v4 = v[4];
	t4 = *tau * v4;
	v5 = v[5];
	t5 = *tau * v5;
	i__1 = *n;
	for (j = 1; j <= i__1; ++j) {
	    sum = v1 * c__[j * c_dim1 + 1] + v2 * c__[j * c_dim1 + 2] + v3 * 
		    c__[j * c_dim1 + 3] + v4 * c__[j * c_dim1 + 4] + v5 * c__[
		    j * c_dim1 + 5];
	    c__[j * c_dim1 + 1] -= sum * t1;
	    c__[j * c_dim1 + 2] -= sum * t2;
	    c__[j * c_dim1 + 3] -= sum * t3;
	    c__[j * c_dim1 + 4] -= sum * t4;
	    c__[j * c_dim1 + 5] -= sum * t5;
/* L100: */
	}
	goto L410;
L110:

/*        Special code for 6 x 6 Householder */

	v1 = v[1];
	t1 = *tau * v1;
	v2 = v[2];
	t2 = *tau * v2;
	v3 = v[3];
	t3 = *tau * v3;
	v4 = v[4];
	t4 = *tau * v4;
	v5 = v[5];
	t5 = *tau * v5;
	v6 = v[6];
	t6 = *tau * v6;
	i__1 = *n;
	for (j = 1; j <= i__1; ++j) {
	    sum = v1 * c__[j * c_dim1 + 1] + v2 * c__[j * c_dim1 + 2] + v3 * 
		    c__[j * c_dim1 + 3] + v4 * c__[j * c_dim1 + 4] + v5 * c__[
		    j * c_dim1 + 5] + v6 * c__[j * c_dim1 + 6];
	    c__[j * c_dim1 + 1] -= sum * t1;
	    c__[j * c_dim1 + 2] -= sum * t2;
	    c__[j * c_dim1 + 3] -= sum * t3;
	    c__[j * c_dim1 + 4] -= sum * t4;
	    c__[j * c_dim1 + 5] -= sum * t5;
	    c__[j * c_dim1 + 6] -= sum * t6;
/* L120: */
	}
	goto L410;
L130:

/*        Special code for 7 x 7 Householder */

	v1 = v[1];
	t1 = *tau * v1;
	v2 = v[2];
	t2 = *tau * v2;
	v3 = v[3];
	t3 = *tau * v3;
	v4 = v[4];
	t4 = *tau * v4;
	v5 = v[5];
	t5 = *tau * v5;
	v6 = v[6];
	t6 = *tau * v6;
	v7 = v[7];
	t7 = *tau * v7;
	i__1 = *n;
	for (j = 1; j <= i__1; ++j) {
	    sum = v1 * c__[j * c_dim1 + 1] + v2 * c__[j * c_dim1 + 2] + v3 * 
		    c__[j * c_dim1 + 3] + v4 * c__[j * c_dim1 + 4] + v5 * c__[
		    j * c_dim1 + 5] + v6 * c__[j * c_dim1 + 6] + v7 * c__[j * 
		    c_dim1 + 7];
	    c__[j * c_dim1 + 1] -= sum * t1;
	    c__[j * c_dim1 + 2] -= sum * t2;
	    c__[j * c_dim1 + 3] -= sum * t3;
	    c__[j * c_dim1 + 4] -= sum * t4;
	    c__[j * c_dim1 + 5] -= sum * t5;
	    c__[j * c_dim1 + 6] -= sum * t6;
	    c__[j * c_dim1 + 7] -= sum * t7;
/* L140: */
	}
	goto L410;
L150:

/*        Special code for 8 x 8 Householder */

	v1 = v[1];
	t1 = *tau * v1;
	v2 = v[2];
	t2 = *tau * v2;
	v3 = v[3];
	t3 = *tau * v3;
	v4 = v[4];
	t4 = *tau * v4;
	v5 = v[5];
	t5 = *tau * v5;
	v6 = v[6];
	t6 = *tau * v6;
	v7 = v[7];
	t7 = *tau * v7;
	v8 = v[8];
	t8 = *tau * v8;
	i__1 = *n;
	for (j = 1; j <= i__1; ++j) {
	    sum = v1 * c__[j * c_dim1 + 1] + v2 * c__[j * c_dim1 + 2] + v3 * 
		    c__[j * c_dim1 + 3] + v4 * c__[j * c_dim1 + 4] + v5 * c__[
		    j * c_dim1 + 5] + v6 * c__[j * c_dim1 + 6] + v7 * c__[j * 
		    c_dim1 + 7] + v8 * c__[j * c_dim1 + 8];
	    c__[j * c_dim1 + 1] -= sum * t1;
	    c__[j * c_dim1 + 2] -= sum * t2;
	    c__[j * c_dim1 + 3] -= sum * t3;
	    c__[j * c_dim1 + 4] -= sum * t4;
	    c__[j * c_dim1 + 5] -= sum * t5;
	    c__[j * c_dim1 + 6] -= sum * t6;
	    c__[j * c_dim1 + 7] -= sum * t7;
	    c__[j * c_dim1 + 8] -= sum * t8;
/* L160: */
	}
	goto L410;
L170:

/*        Special code for 9 x 9 Householder */

	v1 = v[1];
	t1 = *tau * v1;
	v2 = v[2];
	t2 = *tau * v2;
	v3 = v[3];
	t3 = *tau * v3;
	v4 = v[4];
	t4 = *tau * v4;
	v5 = v[5];
	t5 = *tau * v5;
	v6 = v[6];
	t6 = *tau * v6;
	v7 = v[7];
	t7 = *tau * v7;
	v8 = v[8];
	t8 = *tau * v8;
	v9 = v[9];
	t9 = *tau * v9;
	i__1 = *n;
	for (j = 1; j <= i__1; ++j) {
	    sum = v1 * c__[j * c_dim1 + 1] + v2 * c__[j * c_dim1 + 2] + v3 * 
		    c__[j * c_dim1 + 3] + v4 * c__[j * c_dim1 + 4] + v5 * c__[
		    j * c_dim1 + 5] + v6 * c__[j * c_dim1 + 6] + v7 * c__[j * 
		    c_dim1 + 7] + v8 * c__[j * c_dim1 + 8] + v9 * c__[j * 
		    c_dim1 + 9];
	    c__[j * c_dim1 + 1] -= sum * t1;
	    c__[j * c_dim1 + 2] -= sum * t2;
	    c__[j * c_dim1 + 3] -= sum * t3;
	    c__[j * c_dim1 + 4] -= sum * t4;
	    c__[j * c_dim1 + 5] -= sum * t5;
	    c__[j * c_dim1 + 6] -= sum * t6;
	    c__[j * c_dim1 + 7] -= sum * t7;
	    c__[j * c_dim1 + 8] -= sum * t8;
	    c__[j * c_dim1 + 9] -= sum * t9;
/* L180: */
	}
	goto L410;
L190:

/*        Special code for 10 x 10 Householder */

	v1 = v[1];
	t1 = *tau * v1;
	v2 = v[2];
	t2 = *tau * v2;
	v3 = v[3];
	t3 = *tau * v3;
	v4 = v[4];
	t4 = *tau * v4;
	v5 = v[5];
	t5 = *tau * v5;
	v6 = v[6];
	t6 = *tau * v6;
	v7 = v[7];
	t7 = *tau * v7;
	v8 = v[8];
	t8 = *tau * v8;
	v9 = v[9];
	t9 = *tau * v9;
	v10 = v[10];
	t10 = *tau * v10;
	i__1 = *n;
	for (j = 1; j <= i__1; ++j) {
	    sum = v1 * c__[j * c_dim1 + 1] + v2 * c__[j * c_dim1 + 2] + v3 * 
		    c__[j * c_dim1 + 3] + v4 * c__[j * c_dim1 + 4] + v5 * c__[
		    j * c_dim1 + 5] + v6 * c__[j * c_dim1 + 6] + v7 * c__[j * 
		    c_dim1 + 7] + v8 * c__[j * c_dim1 + 8] + v9 * c__[j * 
		    c_dim1 + 9] + v10 * c__[j * c_dim1 + 10];
	    c__[j * c_dim1 + 1] -= sum * t1;
	    c__[j * c_dim1 + 2] -= sum * t2;
	    c__[j * c_dim1 + 3] -= sum * t3;
	    c__[j * c_dim1 + 4] -= sum * t4;
	    c__[j * c_dim1 + 5] -= sum * t5;
	    c__[j * c_dim1 + 6] -= sum * t6;
	    c__[j * c_dim1 + 7] -= sum * t7;
	    c__[j * c_dim1 + 8] -= sum * t8;
	    c__[j * c_dim1 + 9] -= sum * t9;
	    c__[j * c_dim1 + 10] -= sum * t10;
/* L200: */
	}
	goto L410;
    } else {

/*        Form  C * H, where H has order n. */

	switch (*n) {
	    case 1:  goto L210;
	    case 2:  goto L230;
	    case 3:  goto L250;
	    case 4:  goto L270;
	    case 5:  goto L290;
	    case 6:  goto L310;
	    case 7:  goto L330;
	    case 8:  goto L350;
	    case 9:  goto L370;
	    case 10:  goto L390;
	}

/*        Code for general N */

	slarf_(side, m, n, &v[1], &c__1, tau, &c__[c_offset], ldc, &work[1]);
	goto L410;
L210:

/*        Special code for 1 x 1 Householder */

	t1 = 1.f - *tau * v[1] * v[1];
	i__1 = *m;
	for (j = 1; j <= i__1; ++j) {
	    c__[j + c_dim1] = t1 * c__[j + c_dim1];
/* L220: */
	}
	goto L410;
L230:

/*        Special code for 2 x 2 Householder */

	v1 = v[1];
	t1 = *tau * v1;
	v2 = v[2];
	t2 = *tau * v2;
	i__1 = *m;
	for (j = 1; j <= i__1; ++j) {
	    sum = v1 * c__[j + c_dim1] + v2 * c__[j + (c_dim1 << 1)];
	    c__[j + c_dim1] -= sum * t1;
	    c__[j + (c_dim1 << 1)] -= sum * t2;
/* L240: */
	}
	goto L410;
L250:

/*        Special code for 3 x 3 Householder */

	v1 = v[1];
	t1 = *tau * v1;
	v2 = v[2];
	t2 = *tau * v2;
	v3 = v[3];
	t3 = *tau * v3;
	i__1 = *m;
	for (j = 1; j <= i__1; ++j) {
	    sum = v1 * c__[j + c_dim1] + v2 * c__[j + (c_dim1 << 1)] + v3 * 
		    c__[j + c_dim1 * 3];
	    c__[j + c_dim1] -= sum * t1;
	    c__[j + (c_dim1 << 1)] -= sum * t2;
	    c__[j + c_dim1 * 3] -= sum * t3;
/* L260: */
	}
	goto L410;
L270:

/*        Special code for 4 x 4 Householder */

	v1 = v[1];
	t1 = *tau * v1;
	v2 = v[2];
	t2 = *tau * v2;
	v3 = v[3];
	t3 = *tau * v3;
	v4 = v[4];
	t4 = *tau * v4;
	i__1 = *m;
	for (j = 1; j <= i__1; ++j) {
	    sum = v1 * c__[j + c_dim1] + v2 * c__[j + (c_dim1 << 1)] + v3 * 
		    c__[j + c_dim1 * 3] + v4 * c__[j + (c_dim1 << 2)];
	    c__[j + c_dim1] -= sum * t1;
	    c__[j + (c_dim1 << 1)] -= sum * t2;
	    c__[j + c_dim1 * 3] -= sum * t3;
	    c__[j + (c_dim1 << 2)] -= sum * t4;
/* L280: */
	}
	goto L410;
L290:

/*        Special code for 5 x 5 Householder */

	v1 = v[1];
	t1 = *tau * v1;
	v2 = v[2];
	t2 = *tau * v2;
	v3 = v[3];
	t3 = *tau * v3;
	v4 = v[4];
	t4 = *tau * v4;
	v5 = v[5];
	t5 = *tau * v5;
	i__1 = *m;
	for (j = 1; j <= i__1; ++j) {
	    sum = v1 * c__[j + c_dim1] + v2 * c__[j + (c_dim1 << 1)] + v3 * 
		    c__[j + c_dim1 * 3] + v4 * c__[j + (c_dim1 << 2)] + v5 * 
		    c__[j + c_dim1 * 5];
	    c__[j + c_dim1] -= sum * t1;
	    c__[j + (c_dim1 << 1)] -= sum * t2;
	    c__[j + c_dim1 * 3] -= sum * t3;
	    c__[j + (c_dim1 << 2)] -= sum * t4;
	    c__[j + c_dim1 * 5] -= sum * t5;
/* L300: */
	}
	goto L410;
L310:

/*        Special code for 6 x 6 Householder */

	v1 = v[1];
	t1 = *tau * v1;
	v2 = v[2];
	t2 = *tau * v2;
	v3 = v[3];
	t3 = *tau * v3;
	v4 = v[4];
	t4 = *tau * v4;
	v5 = v[5];
	t5 = *tau * v5;
	v6 = v[6];
	t6 = *tau * v6;
	i__1 = *m;
	for (j = 1; j <= i__1; ++j) {
	    sum = v1 * c__[j + c_dim1] + v2 * c__[j + (c_dim1 << 1)] + v3 * 
		    c__[j + c_dim1 * 3] + v4 * c__[j + (c_dim1 << 2)] + v5 * 
		    c__[j + c_dim1 * 5] + v6 * c__[j + c_dim1 * 6];
	    c__[j + c_dim1] -= sum * t1;
	    c__[j + (c_dim1 << 1)] -= sum * t2;
	    c__[j + c_dim1 * 3] -= sum * t3;
	    c__[j + (c_dim1 << 2)] -= sum * t4;
	    c__[j + c_dim1 * 5] -= sum * t5;
	    c__[j + c_dim1 * 6] -= sum * t6;
/* L320: */
	}
	goto L410;
L330:

/*        Special code for 7 x 7 Householder */

	v1 = v[1];
	t1 = *tau * v1;
	v2 = v[2];
	t2 = *tau * v2;
	v3 = v[3];
	t3 = *tau * v3;
	v4 = v[4];
	t4 = *tau * v4;
	v5 = v[5];
	t5 = *tau * v5;
	v6 = v[6];
	t6 = *tau * v6;
	v7 = v[7];
	t7 = *tau * v7;
	i__1 = *m;
	for (j = 1; j <= i__1; ++j) {
	    sum = v1 * c__[j + c_dim1] + v2 * c__[j + (c_dim1 << 1)] + v3 * 
		    c__[j + c_dim1 * 3] + v4 * c__[j + (c_dim1 << 2)] + v5 * 
		    c__[j + c_dim1 * 5] + v6 * c__[j + c_dim1 * 6] + v7 * c__[
		    j + c_dim1 * 7];
	    c__[j + c_dim1] -= sum * t1;
	    c__[j + (c_dim1 << 1)] -= sum * t2;
	    c__[j + c_dim1 * 3] -= sum * t3;
	    c__[j + (c_dim1 << 2)] -= sum * t4;
	    c__[j + c_dim1 * 5] -= sum * t5;
	    c__[j + c_dim1 * 6] -= sum * t6;
	    c__[j + c_dim1 * 7] -= sum * t7;
/* L340: */
	}
	goto L410;
L350:

/*        Special code for 8 x 8 Householder */

	v1 = v[1];
	t1 = *tau * v1;
	v2 = v[2];
	t2 = *tau * v2;
	v3 = v[3];
	t3 = *tau * v3;
	v4 = v[4];
	t4 = *tau * v4;
	v5 = v[5];
	t5 = *tau * v5;
	v6 = v[6];
	t6 = *tau * v6;
	v7 = v[7];
	t7 = *tau * v7;
	v8 = v[8];
	t8 = *tau * v8;
	i__1 = *m;
	for (j = 1; j <= i__1; ++j) {
	    sum = v1 * c__[j + c_dim1] + v2 * c__[j + (c_dim1 << 1)] + v3 * 
		    c__[j + c_dim1 * 3] + v4 * c__[j + (c_dim1 << 2)] + v5 * 
		    c__[j + c_dim1 * 5] + v6 * c__[j + c_dim1 * 6] + v7 * c__[
		    j + c_dim1 * 7] + v8 * c__[j + (c_dim1 << 3)];
	    c__[j + c_dim1] -= sum * t1;
	    c__[j + (c_dim1 << 1)] -= sum * t2;
	    c__[j + c_dim1 * 3] -= sum * t3;
	    c__[j + (c_dim1 << 2)] -= sum * t4;
	    c__[j + c_dim1 * 5] -= sum * t5;
	    c__[j + c_dim1 * 6] -= sum * t6;
	    c__[j + c_dim1 * 7] -= sum * t7;
	    c__[j + (c_dim1 << 3)] -= sum * t8;
/* L360: */
	}
	goto L410;
L370:

/*        Special code for 9 x 9 Householder */

	v1 = v[1];
	t1 = *tau * v1;
	v2 = v[2];
	t2 = *tau * v2;
	v3 = v[3];
	t3 = *tau * v3;
	v4 = v[4];
	t4 = *tau * v4;
	v5 = v[5];
	t5 = *tau * v5;
	v6 = v[6];
	t6 = *tau * v6;
	v7 = v[7];
	t7 = *tau * v7;
	v8 = v[8];
	t8 = *tau * v8;
	v9 = v[9];
	t9 = *tau * v9;
	i__1 = *m;
	for (j = 1; j <= i__1; ++j) {
	    sum = v1 * c__[j + c_dim1] + v2 * c__[j + (c_dim1 << 1)] + v3 * 
		    c__[j + c_dim1 * 3] + v4 * c__[j + (c_dim1 << 2)] + v5 * 
		    c__[j + c_dim1 * 5] + v6 * c__[j + c_dim1 * 6] + v7 * c__[
		    j + c_dim1 * 7] + v8 * c__[j + (c_dim1 << 3)] + v9 * c__[
		    j + c_dim1 * 9];
	    c__[j + c_dim1] -= sum * t1;
	    c__[j + (c_dim1 << 1)] -= sum * t2;
	    c__[j + c_dim1 * 3] -= sum * t3;
	    c__[j + (c_dim1 << 2)] -= sum * t4;
	    c__[j + c_dim1 * 5] -= sum * t5;
	    c__[j + c_dim1 * 6] -= sum * t6;
	    c__[j + c_dim1 * 7] -= sum * t7;
	    c__[j + (c_dim1 << 3)] -= sum * t8;
	    c__[j + c_dim1 * 9] -= sum * t9;
/* L380: */
	}
	goto L410;
L390:

/*        Special code for 10 x 10 Householder */

	v1 = v[1];
	t1 = *tau * v1;
	v2 = v[2];
	t2 = *tau * v2;
	v3 = v[3];
	t3 = *tau * v3;
	v4 = v[4];
	t4 = *tau * v4;
	v5 = v[5];
	t5 = *tau * v5;
	v6 = v[6];
	t6 = *tau * v6;
	v7 = v[7];
	t7 = *tau * v7;
	v8 = v[8];
	t8 = *tau * v8;
	v9 = v[9];
	t9 = *tau * v9;
	v10 = v[10];
	t10 = *tau * v10;
	i__1 = *m;
	for (j = 1; j <= i__1; ++j) {
	    sum = v1 * c__[j + c_dim1] + v2 * c__[j + (c_dim1 << 1)] + v3 * 
		    c__[j + c_dim1 * 3] + v4 * c__[j + (c_dim1 << 2)] + v5 * 
		    c__[j + c_dim1 * 5] + v6 * c__[j + c_dim1 * 6] + v7 * c__[
		    j + c_dim1 * 7] + v8 * c__[j + (c_dim1 << 3)] + v9 * c__[
		    j + c_dim1 * 9] + v10 * c__[j + c_dim1 * 10];
	    c__[j + c_dim1] -= sum * t1;
	    c__[j + (c_dim1 << 1)] -= sum * t2;
	    c__[j + c_dim1 * 3] -= sum * t3;
	    c__[j + (c_dim1 << 2)] -= sum * t4;
	    c__[j + c_dim1 * 5] -= sum * t5;
	    c__[j + c_dim1 * 6] -= sum * t6;
	    c__[j + c_dim1 * 7] -= sum * t7;
	    c__[j + (c_dim1 << 3)] -= sum * t8;
	    c__[j + c_dim1 * 9] -= sum * t9;
	    c__[j + c_dim1 * 10] -= sum * t10;
/* L400: */
	}
	goto L410;
    }
L410:
    return 0;

/*     End of SLARFX */

} /* slarfx_ */
Esempio n. 18
0
/* Subroutine */
int sormr2_(char *side, char *trans, integer *m, integer *n, integer *k, real *a, integer *lda, real *tau, real *c__, integer *ldc, real *work, integer *info)
{
    /* System generated locals */
    integer a_dim1, a_offset, c_dim1, c_offset, i__1, i__2;
    /* Local variables */
    integer i__, i1, i2, i3, mi, ni, nq;
    real aii;
    logical left;
    extern logical lsame_(char *, char *);
    extern /* Subroutine */
    int slarf_(char *, integer *, integer *, real *, integer *, real *, real *, integer *, real *), xerbla_( char *, integer *);
    logical notran;
    /* -- LAPACK computational routine (version 3.4.2) -- */
    /* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
    /* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
    /* September 2012 */
    /* .. Scalar Arguments .. */
    /* .. */
    /* .. Array Arguments .. */
    /* .. */
    /* ===================================================================== */
    /* .. Parameters .. */
    /* .. */
    /* .. Local Scalars .. */
    /* .. */
    /* .. External Functions .. */
    /* .. */
    /* .. External Subroutines .. */
    /* .. */
    /* .. Intrinsic Functions .. */
    /* .. */
    /* .. Executable Statements .. */
    /* Test the input arguments */
    /* Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    --tau;
    c_dim1 = *ldc;
    c_offset = 1 + c_dim1;
    c__ -= c_offset;
    --work;
    /* Function Body */
    *info = 0;
    left = lsame_(side, "L");
    notran = lsame_(trans, "N");
    /* NQ is the order of Q */
    if (left)
    {
        nq = *m;
    }
    else
    {
        nq = *n;
    }
    if (! left && ! lsame_(side, "R"))
    {
        *info = -1;
    }
    else if (! notran && ! lsame_(trans, "T"))
    {
        *info = -2;
    }
    else if (*m < 0)
    {
        *info = -3;
    }
    else if (*n < 0)
    {
        *info = -4;
    }
    else if (*k < 0 || *k > nq)
    {
        *info = -5;
    }
    else if (*lda < max(1,*k))
    {
        *info = -7;
    }
    else if (*ldc < max(1,*m))
    {
        *info = -10;
    }
    if (*info != 0)
    {
        i__1 = -(*info);
        xerbla_("SORMR2", &i__1);
        return 0;
    }
    /* Quick return if possible */
    if (*m == 0 || *n == 0 || *k == 0)
    {
        return 0;
    }
    if (left && ! notran || ! left && notran)
    {
        i1 = 1;
        i2 = *k;
        i3 = 1;
    }
    else
    {
        i1 = *k;
        i2 = 1;
        i3 = -1;
    }
    if (left)
    {
        ni = *n;
    }
    else
    {
        mi = *m;
    }
    i__1 = i2;
    i__2 = i3;
    for (i__ = i1;
            i__2 < 0 ? i__ >= i__1 : i__ <= i__1;
            i__ += i__2)
    {
        if (left)
        {
            /* H(i) is applied to C(1:m-k+i,1:n) */
            mi = *m - *k + i__;
        }
        else
        {
            /* H(i) is applied to C(1:m,1:n-k+i) */
            ni = *n - *k + i__;
        }
        /* Apply H(i) */
        aii = a[i__ + (nq - *k + i__) * a_dim1];
        a[i__ + (nq - *k + i__) * a_dim1] = 1.f;
        slarf_(side, &mi, &ni, &a[i__ + a_dim1], lda, &tau[i__], &c__[ c_offset], ldc, &work[1]);
        a[i__ + (nq - *k + i__) * a_dim1] = aii;
        /* L10: */
    }
    return 0;
    /* End of SORMR2 */
}
Esempio n. 19
0
/* Subroutine */ int sormr2_(char *side, char *trans, integer *m, integer *n, 
	integer *k, real *a, integer *lda, real *tau, real *c__, integer *ldc,
	 real *work, integer *info, ftnlen side_len, ftnlen trans_len)
{
    /* System generated locals */
    integer a_dim1, a_offset, c_dim1, c_offset, i__1, i__2;

    /* Local variables */
    static integer i__, i1, i2, i3, mi, ni, nq;
    static real aii;
    static logical left;
    extern logical lsame_(char *, char *, ftnlen, ftnlen);
    extern /* Subroutine */ int slarf_(char *, integer *, integer *, real *, 
	    integer *, real *, real *, integer *, real *, ftnlen), xerbla_(
	    char *, integer *, ftnlen);
    static logical notran;


/*  -- LAPACK routine (version 3.0) -- */
/*     Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd., */
/*     Courant Institute, Argonne National Lab, and Rice University */
/*     February 29, 1992 */

/*     .. Scalar Arguments .. */
/*     .. */
/*     .. Array Arguments .. */
/*     .. */

/*  Purpose */
/*  ======= */

/*  SORMR2 overwrites the general real m by n matrix C with */

/*        Q * C  if SIDE = 'L' and TRANS = 'N', or */

/*        Q'* C  if SIDE = 'L' and TRANS = 'T', or */

/*        C * Q  if SIDE = 'R' and TRANS = 'N', or */

/*        C * Q' if SIDE = 'R' and TRANS = 'T', */

/*  where Q is a real orthogonal matrix defined as the product of k */
/*  elementary reflectors */

/*        Q = H(1) H(2) . . . H(k) */

/*  as returned by SGERQF. Q is of order m if SIDE = 'L' and of order n */
/*  if SIDE = 'R'. */

/*  Arguments */
/*  ========= */

/*  SIDE    (input) CHARACTER*1 */
/*          = 'L': apply Q or Q' from the Left */
/*          = 'R': apply Q or Q' from the Right */

/*  TRANS   (input) CHARACTER*1 */
/*          = 'N': apply Q  (No transpose) */
/*          = 'T': apply Q' (Transpose) */

/*  M       (input) INTEGER */
/*          The number of rows of the matrix C. M >= 0. */

/*  N       (input) INTEGER */
/*          The number of columns of the matrix C. N >= 0. */

/*  K       (input) INTEGER */
/*          The number of elementary reflectors whose product defines */
/*          the matrix Q. */
/*          If SIDE = 'L', M >= K >= 0; */
/*          if SIDE = 'R', N >= K >= 0. */

/*  A       (input) REAL array, dimension */
/*                               (LDA,M) if SIDE = 'L', */
/*                               (LDA,N) if SIDE = 'R' */
/*          The i-th row must contain the vector which defines the */
/*          elementary reflector H(i), for i = 1,2,...,k, as returned by */
/*          SGERQF in the last k rows of its array argument A. */
/*          A is modified by the routine but restored on exit. */

/*  LDA     (input) INTEGER */
/*          The leading dimension of the array A. LDA >= max(1,K). */

/*  TAU     (input) REAL array, dimension (K) */
/*          TAU(i) must contain the scalar factor of the elementary */
/*          reflector H(i), as returned by SGERQF. */

/*  C       (input/output) REAL array, dimension (LDC,N) */
/*          On entry, the m by n matrix C. */
/*          On exit, C is overwritten by Q*C or Q'*C or C*Q' or C*Q. */

/*  LDC     (input) INTEGER */
/*          The leading dimension of the array C. LDC >= max(1,M). */

/*  WORK    (workspace) REAL array, dimension */
/*                                   (N) if SIDE = 'L', */
/*                                   (M) if SIDE = 'R' */

/*  INFO    (output) INTEGER */
/*          = 0: successful exit */
/*          < 0: if INFO = -i, the i-th argument had an illegal value */

/*  ===================================================================== */

/*     .. Parameters .. */
/*     .. */
/*     .. Local Scalars .. */
/*     .. */
/*     .. External Functions .. */
/*     .. */
/*     .. External Subroutines .. */
/*     .. */
/*     .. Intrinsic Functions .. */
/*     .. */
/*     .. Executable Statements .. */

/*     Test the input arguments */

    /* Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    --tau;
    c_dim1 = *ldc;
    c_offset = 1 + c_dim1;
    c__ -= c_offset;
    --work;

    /* Function Body */
    *info = 0;
    left = lsame_(side, "L", (ftnlen)1, (ftnlen)1);
    notran = lsame_(trans, "N", (ftnlen)1, (ftnlen)1);

/*     NQ is the order of Q */

    if (left) {
	nq = *m;
    } else {
	nq = *n;
    }
    if (! left && ! lsame_(side, "R", (ftnlen)1, (ftnlen)1)) {
	*info = -1;
    } else if (! notran && ! lsame_(trans, "T", (ftnlen)1, (ftnlen)1)) {
	*info = -2;
    } else if (*m < 0) {
	*info = -3;
    } else if (*n < 0) {
	*info = -4;
    } else if (*k < 0 || *k > nq) {
	*info = -5;
    } else if (*lda < max(1,*k)) {
	*info = -7;
    } else if (*ldc < max(1,*m)) {
	*info = -10;
    }
    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("SORMR2", &i__1, (ftnlen)6);
	return 0;
    }

/*     Quick return if possible */

    if (*m == 0 || *n == 0 || *k == 0) {
	return 0;
    }

    if (left && ! notran || ! left && notran) {
	i1 = 1;
	i2 = *k;
	i3 = 1;
    } else {
	i1 = *k;
	i2 = 1;
	i3 = -1;
    }

    if (left) {
	ni = *n;
    } else {
	mi = *m;
    }

    i__1 = i2;
    i__2 = i3;
    for (i__ = i1; i__2 < 0 ? i__ >= i__1 : i__ <= i__1; i__ += i__2) {
	if (left) {

/*           H(i) is applied to C(1:m-k+i,1:n) */

	    mi = *m - *k + i__;
	} else {

/*           H(i) is applied to C(1:m,1:n-k+i) */

	    ni = *n - *k + i__;
	}

/*        Apply H(i) */

	aii = a[i__ + (nq - *k + i__) * a_dim1];
	a[i__ + (nq - *k + i__) * a_dim1] = 1.f;
	slarf_(side, &mi, &ni, &a[i__ + a_dim1], lda, &tau[i__], &c__[
		c_offset], ldc, &work[1], (ftnlen)1);
	a[i__ + (nq - *k + i__) * a_dim1] = aii;
/* L10: */
    }
    return 0;

/*     End of SORMR2 */

} /* sormr2_ */
Esempio n. 20
0
File: sorm2r.c Progetto: axel971/itk
/*<    >*/
/* Subroutine */ int sorm2r_(char *side, char *trans, integer *m, integer *n, 
        integer *k, real *a, integer *lda, real *tau, real *c__, integer *ldc,
         real *work, integer *info, ftnlen side_len, ftnlen trans_len)
{
    /* System generated locals */
    integer a_dim1, a_offset, c_dim1, c_offset, i__1, i__2;

    /* Local variables */
    integer i__, i1, i2, i3, ic=0, jc=0, mi, ni, nq;
    real aii;
    logical left;
    extern logical lsame_(char *, char *, ftnlen, ftnlen);
    extern /* Subroutine */ int slarf_(char *, integer *, integer *, real *, 
            integer *, real *, real *, integer *, real *, ftnlen), xerbla_(
            char *, integer *, ftnlen);
    logical notran;
    (void)side_len;
    (void)trans_len;

/*  -- LAPACK routine (version 3.0) -- */
/*     Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd., */
/*     Courant Institute, Argonne National Lab, and Rice University */
/*     February 29, 1992 */

/*     .. Scalar Arguments .. */
/*<       CHARACTER          SIDE, TRANS >*/
/*<       INTEGER            INFO, K, LDA, LDC, M, N >*/
/*     .. */
/*     .. Array Arguments .. */
/*<       REAL               A( LDA, * ), C( LDC, * ), TAU( * ), WORK( * ) >*/
/*     .. */

/*  Purpose */
/*  ======= */

/*  SORM2R overwrites the general real m by n matrix C with */

/*        Q * C  if SIDE = 'L' and TRANS = 'N', or */

/*        Q'* C  if SIDE = 'L' and TRANS = 'T', or */

/*        C * Q  if SIDE = 'R' and TRANS = 'N', or */

/*        C * Q' if SIDE = 'R' and TRANS = 'T', */

/*  where Q is a real orthogonal matrix defined as the product of k */
/*  elementary reflectors */

/*        Q = H(1) H(2) . . . H(k) */

/*  as returned by SGEQRF. Q is of order m if SIDE = 'L' and of order n */
/*  if SIDE = 'R'. */

/*  Arguments */
/*  ========= */

/*  SIDE    (input) CHARACTER*1 */
/*          = 'L': apply Q or Q' from the Left */
/*          = 'R': apply Q or Q' from the Right */

/*  TRANS   (input) CHARACTER*1 */
/*          = 'N': apply Q  (No transpose) */
/*          = 'T': apply Q' (Transpose) */

/*  M       (input) INTEGER */
/*          The number of rows of the matrix C. M >= 0. */

/*  N       (input) INTEGER */
/*          The number of columns of the matrix C. N >= 0. */

/*  K       (input) INTEGER */
/*          The number of elementary reflectors whose product defines */
/*          the matrix Q. */
/*          If SIDE = 'L', M >= K >= 0; */
/*          if SIDE = 'R', N >= K >= 0. */

/*  A       (input) REAL array, dimension (LDA,K) */
/*          The i-th column must contain the vector which defines the */
/*          elementary reflector H(i), for i = 1,2,...,k, as returned by */
/*          SGEQRF in the first k columns of its array argument A. */
/*          A is modified by the routine but restored on exit. */

/*  LDA     (input) INTEGER */
/*          The leading dimension of the array A. */
/*          If SIDE = 'L', LDA >= max(1,M); */
/*          if SIDE = 'R', LDA >= max(1,N). */

/*  TAU     (input) REAL array, dimension (K) */
/*          TAU(i) must contain the scalar factor of the elementary */
/*          reflector H(i), as returned by SGEQRF. */

/*  C       (input/output) REAL array, dimension (LDC,N) */
/*          On entry, the m by n matrix C. */
/*          On exit, C is overwritten by Q*C or Q'*C or C*Q' or C*Q. */

/*  LDC     (input) INTEGER */
/*          The leading dimension of the array C. LDC >= max(1,M). */

/*  WORK    (workspace) REAL array, dimension */
/*                                   (N) if SIDE = 'L', */
/*                                   (M) if SIDE = 'R' */

/*  INFO    (output) INTEGER */
/*          = 0: successful exit */
/*          < 0: if INFO = -i, the i-th argument had an illegal value */

/*  ===================================================================== */

/*     .. Parameters .. */
/*<       REAL               ONE >*/
/*<       PARAMETER          ( ONE = 1.0E+0 ) >*/
/*     .. */
/*     .. Local Scalars .. */
/*<       LOGICAL            LEFT, NOTRAN >*/
/*<       INTEGER            I, I1, I2, I3, IC, JC, MI, NI, NQ >*/
/*<       REAL               AII >*/
/*     .. */
/*     .. External Functions .. */
/*<       LOGICAL            LSAME >*/
/*<       EXTERNAL           LSAME >*/
/*     .. */
/*     .. External Subroutines .. */
/*<       EXTERNAL           SLARF, XERBLA >*/
/*     .. */
/*     .. Intrinsic Functions .. */
/*<       INTRINSIC          MAX >*/
/*     .. */
/*     .. Executable Statements .. */

/*     Test the input arguments */

/*<       INFO = 0 >*/
    /* Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    --tau;
    c_dim1 = *ldc;
    c_offset = 1 + c_dim1;
    c__ -= c_offset;
    --work;

    /* Function Body */
    *info = 0;
/*<       LEFT = LSAME( SIDE, 'L' ) >*/
    left = lsame_(side, "L", (ftnlen)1, (ftnlen)1);
/*<       NOTRAN = LSAME( TRANS, 'N' ) >*/
    notran = lsame_(trans, "N", (ftnlen)1, (ftnlen)1);

/*     NQ is the order of Q */

/*<       IF( LEFT ) THEN >*/
    if (left) {
/*<          NQ = M >*/
        nq = *m;
/*<       ELSE >*/
    } else {
/*<          NQ = N >*/
        nq = *n;
/*<       END IF >*/
    }
/*<       IF( .NOT.LEFT .AND. .NOT.LSAME( SIDE, 'R' ) ) THEN >*/
    if (! left && ! lsame_(side, "R", (ftnlen)1, (ftnlen)1)) {
/*<          INFO = -1 >*/
        *info = -1;
/*<       ELSE IF( .NOT.NOTRAN .AND. .NOT.LSAME( TRANS, 'T' ) ) THEN >*/
    } else if (! notran && ! lsame_(trans, "T", (ftnlen)1, (ftnlen)1)) {
/*<          INFO = -2 >*/
        *info = -2;
/*<       ELSE IF( M.LT.0 ) THEN >*/
    } else if (*m < 0) {
/*<          INFO = -3 >*/
        *info = -3;
/*<       ELSE IF( N.LT.0 ) THEN >*/
    } else if (*n < 0) {
/*<          INFO = -4 >*/
        *info = -4;
/*<       ELSE IF( K.LT.0 .OR. K.GT.NQ ) THEN >*/
    } else if (*k < 0 || *k > nq) {
/*<          INFO = -5 >*/
        *info = -5;
/*<       ELSE IF( LDA.LT.MAX( 1, NQ ) ) THEN >*/
    } else if (*lda < max(1,nq)) {
/*<          INFO = -7 >*/
        *info = -7;
/*<       ELSE IF( LDC.LT.MAX( 1, M ) ) THEN >*/
    } else if (*ldc < max(1,*m)) {
/*<          INFO = -10 >*/
        *info = -10;
/*<       END IF >*/
    }
/*<       IF( INFO.NE.0 ) THEN >*/
    if (*info != 0) {
/*<          CALL XERBLA( 'SORM2R', -INFO ) >*/
        i__1 = -(*info);
        xerbla_("SORM2R", &i__1, (ftnlen)6);
/*<          RETURN >*/
        return 0;
/*<       END IF >*/
    }

/*     Quick return if possible */

/*<    >*/
    if (*m == 0 || *n == 0 || *k == 0) {
        return 0;
    }

/*<    >*/
    if ((left && ! notran) || (! left && notran)) {
/*<          I1 = 1 >*/
        i1 = 1;
/*<          I2 = K >*/
        i2 = *k;
/*<          I3 = 1 >*/
        i3 = 1;
/*<       ELSE >*/
    } else {
/*<          I1 = K >*/
        i1 = *k;
/*<          I2 = 1 >*/
        i2 = 1;
/*<          I3 = -1 >*/
        i3 = -1;
/*<       END IF >*/
    }

/*<       IF( LEFT ) THEN >*/
    if (left) {
/*<          NI = N >*/
        ni = *n;
/*<          JC = 1 >*/
        jc = 1;
/*<       ELSE >*/
    } else {
/*<          MI = M >*/
        mi = *m;
/*<          IC = 1 >*/
        ic = 1;
/*<       END IF >*/
    }

/*<       DO 10 I = I1, I2, I3 >*/
    i__1 = i2;
    i__2 = i3;
    for (i__ = i1; i__2 < 0 ? i__ >= i__1 : i__ <= i__1; i__ += i__2) {
/*<          IF( LEFT ) THEN >*/
        if (left) {

/*           H(i) is applied to C(i:m,1:n) */

/*<             MI = M - I + 1 >*/
            mi = *m - i__ + 1;
/*<             IC = I >*/
            ic = i__;
/*<          ELSE >*/
        } else {

/*           H(i) is applied to C(1:m,i:n) */

/*<             NI = N - I + 1 >*/
            ni = *n - i__ + 1;
/*<             JC = I >*/
            jc = i__;
/*<          END IF >*/
        }

/*        Apply H(i) */

/*<          AII = A( I, I ) >*/
        aii = a[i__ + i__ * a_dim1];
/*<          A( I, I ) = ONE >*/
        a[i__ + i__ * a_dim1] = (float)1.;
/*<    >*/
        slarf_(side, &mi, &ni, &a[i__ + i__ * a_dim1], &c__1, &tau[i__], &c__[
                ic + jc * c_dim1], ldc, &work[1], (ftnlen)1);
/*<          A( I, I ) = AII >*/
        a[i__ + i__ * a_dim1] = aii;
/*<    10 CONTINUE >*/
/* L10: */
    }
/*<       RETURN >*/
    return 0;

/*     End of SORM2R */

/*<       END >*/
} /* sorm2r_ */
Esempio n. 21
0
/* Subroutine */ int sgerq2_(integer *m, integer *n, real *a, integer *lda, 
	real *tau, real *work, integer *info)
{
    /* System generated locals */
    integer a_dim1, a_offset, i__1, i__2;

    /* Local variables */
    integer i__, k;
    real aii;
    extern /* Subroutine */ int slarf_(char *, integer *, integer *, real *, 
	    integer *, real *, real *, integer *, real *), xerbla_(
	    char *, integer *), slarfg_(integer *, real *, real *, 
	    integer *, real *);


/*  -- LAPACK routine (version 3.1) -- */
/*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/*     November 2006 */

/*     .. Scalar Arguments .. */
/*     .. */
/*     .. Array Arguments .. */
/*     .. */

/*  Purpose */
/*  ======= */

/*  SGERQ2 computes an RQ factorization of a real m by n matrix A: */
/*  A = R * Q. */

/*  Arguments */
/*  ========= */

/*  M       (input) INTEGER */
/*          The number of rows of the matrix A.  M >= 0. */

/*  N       (input) INTEGER */
/*          The number of columns of the matrix A.  N >= 0. */

/*  A       (input/output) REAL array, dimension (LDA,N) */
/*          On entry, the m by n matrix A. */
/*          On exit, if m <= n, the upper triangle of the subarray */
/*          A(1:m,n-m+1:n) contains the m by m upper triangular matrix R; */
/*          if m >= n, the elements on and above the (m-n)-th subdiagonal */
/*          contain the m by n upper trapezoidal matrix R; the remaining */
/*          elements, with the array TAU, represent the orthogonal matrix */
/*          Q as a product of elementary reflectors (see Further */
/*          Details). */

/*  LDA     (input) INTEGER */
/*          The leading dimension of the array A.  LDA >= max(1,M). */

/*  TAU     (output) REAL array, dimension (min(M,N)) */
/*          The scalar factors of the elementary reflectors (see Further */
/*          Details). */

/*  WORK    (workspace) REAL array, dimension (M) */

/*  INFO    (output) INTEGER */
/*          = 0: successful exit */
/*          < 0: if INFO = -i, the i-th argument had an illegal value */

/*  Further Details */
/*  =============== */

/*  The matrix Q is represented as a product of elementary reflectors */

/*     Q = H(1) H(2) . . . H(k), where k = min(m,n). */

/*  Each H(i) has the form */

/*     H(i) = I - tau * v * v' */

/*  where tau is a real scalar, and v is a real vector with */
/*  v(n-k+i+1:n) = 0 and v(n-k+i) = 1; v(1:n-k+i-1) is stored on exit in */
/*  A(m-k+i,1:n-k+i-1), and tau in TAU(i). */

/*  ===================================================================== */

/*     .. Parameters .. */
/*     .. */
/*     .. Local Scalars .. */
/*     .. */
/*     .. External Subroutines .. */
/*     .. */
/*     .. Intrinsic Functions .. */
/*     .. */
/*     .. Executable Statements .. */

/*     Test the input arguments */

    /* Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    --tau;
    --work;

    /* Function Body */
    *info = 0;
    if (*m < 0) {
	*info = -1;
    } else if (*n < 0) {
	*info = -2;
    } else if (*lda < max(1,*m)) {
	*info = -4;
    }
    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("SGERQ2", &i__1);
	return 0;
    }

    k = min(*m,*n);

    for (i__ = k; i__ >= 1; --i__) {

/*        Generate elementary reflector H(i) to annihilate */
/*        A(m-k+i,1:n-k+i-1) */

	i__1 = *n - k + i__;
	slarfg_(&i__1, &a[*m - k + i__ + (*n - k + i__) * a_dim1], &a[*m - k 
		+ i__ + a_dim1], lda, &tau[i__]);

/*        Apply H(i) to A(1:m-k+i-1,1:n-k+i) from the right */

	aii = a[*m - k + i__ + (*n - k + i__) * a_dim1];
	a[*m - k + i__ + (*n - k + i__) * a_dim1] = 1.f;
	i__1 = *m - k + i__ - 1;
	i__2 = *n - k + i__;
	slarf_("Right", &i__1, &i__2, &a[*m - k + i__ + a_dim1], lda, &tau[
		i__], &a[a_offset], lda, &work[1]);
	a[*m - k + i__ + (*n - k + i__) * a_dim1] = aii;
/* L10: */
    }
    return 0;

/*     End of SGERQ2 */

} /* sgerq2_ */
Esempio n. 22
0
/* Subroutine */
int slaqr2_(logical *wantt, logical *wantz, integer *n, integer *ktop, integer *kbot, integer *nw, real *h__, integer *ldh, integer *iloz, integer *ihiz, real *z__, integer *ldz, integer *ns, integer *nd, real *sr, real *si, real *v, integer *ldv, integer *nh, real *t, integer *ldt, integer *nv, real *wv, integer *ldwv, real * work, integer *lwork)
{
    /* System generated locals */
    integer h_dim1, h_offset, t_dim1, t_offset, v_dim1, v_offset, wv_dim1, wv_offset, z_dim1, z_offset, i__1, i__2, i__3, i__4;
    real r__1, r__2, r__3, r__4, r__5, r__6;
    /* Builtin functions */
    double sqrt(doublereal);
    /* Local variables */
    integer i__, j, k;
    real s, aa, bb, cc, dd, cs, sn;
    integer jw;
    real evi, evk, foo;
    integer kln;
    real tau, ulp;
    integer lwk1, lwk2;
    real beta;
    integer kend, kcol, info, ifst, ilst, ltop, krow;
    logical bulge;
    extern /* Subroutine */
    int slarf_(char *, integer *, integer *, real *, integer *, real *, real *, integer *, real *), sgemm_( char *, char *, integer *, integer *, integer *, real *, real *, integer *, real *, integer *, real *, real *, integer *);
    integer infqr;
    extern /* Subroutine */
    int scopy_(integer *, real *, integer *, real *, integer *);
    integer kwtop;
    extern /* Subroutine */
    int slanv2_(real *, real *, real *, real *, real * , real *, real *, real *, real *, real *), slabad_(real *, real *) ;
    extern real slamch_(char *);
    extern /* Subroutine */
    int sgehrd_(integer *, integer *, integer *, real *, integer *, real *, real *, integer *, integer *);
    real safmin;
    extern /* Subroutine */
    int slarfg_(integer *, real *, real *, integer *, real *);
    real safmax;
    extern /* Subroutine */
    int slahqr_(logical *, logical *, integer *, integer *, integer *, real *, integer *, real *, real *, integer * , integer *, real *, integer *, integer *), slacpy_(char *, integer *, integer *, real *, integer *, real *, integer *), slaset_(char *, integer *, integer *, real *, real *, real *, integer *);
    logical sorted;
    extern /* Subroutine */
    int strexc_(char *, integer *, real *, integer *, real *, integer *, integer *, integer *, real *, integer *), sormhr_(char *, char *, integer *, integer *, integer *, integer *, real *, integer *, real *, real *, integer *, real *, integer *, integer *);
    real smlnum;
    integer lwkopt;
    /* -- LAPACK auxiliary routine (version 3.4.2) -- */
    /* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
    /* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
    /* September 2012 */
    /* .. Scalar Arguments .. */
    /* .. */
    /* .. Array Arguments .. */
    /* .. */
    /* ================================================================ */
    /* .. Parameters .. */
    /* .. */
    /* .. Local Scalars .. */
    /* .. */
    /* .. External Functions .. */
    /* .. */
    /* .. External Subroutines .. */
    /* .. */
    /* .. Intrinsic Functions .. */
    /* .. */
    /* .. Executable Statements .. */
    /* ==== Estimate optimal workspace. ==== */
    /* Parameter adjustments */
    h_dim1 = *ldh;
    h_offset = 1 + h_dim1;
    h__ -= h_offset;
    z_dim1 = *ldz;
    z_offset = 1 + z_dim1;
    z__ -= z_offset;
    --sr;
    --si;
    v_dim1 = *ldv;
    v_offset = 1 + v_dim1;
    v -= v_offset;
    t_dim1 = *ldt;
    t_offset = 1 + t_dim1;
    t -= t_offset;
    wv_dim1 = *ldwv;
    wv_offset = 1 + wv_dim1;
    wv -= wv_offset;
    --work;
    /* Function Body */
    /* Computing MIN */
    i__1 = *nw;
    i__2 = *kbot - *ktop + 1; // , expr subst
    jw = min(i__1,i__2);
    if (jw <= 2)
    {
        lwkopt = 1;
    }
    else
    {
        /* ==== Workspace query call to SGEHRD ==== */
        i__1 = jw - 1;
        sgehrd_(&jw, &c__1, &i__1, &t[t_offset], ldt, &work[1], &work[1], & c_n1, &info);
        lwk1 = (integer) work[1];
        /* ==== Workspace query call to SORMHR ==== */
        i__1 = jw - 1;
        sormhr_("R", "N", &jw, &jw, &c__1, &i__1, &t[t_offset], ldt, &work[1], &v[v_offset], ldv, &work[1], &c_n1, &info);
        lwk2 = (integer) work[1];
        /* ==== Optimal workspace ==== */
        lwkopt = jw + max(lwk1,lwk2);
    }
    /* ==== Quick return in case of workspace query. ==== */
    if (*lwork == -1)
    {
        work[1] = (real) lwkopt;
        return 0;
    }
    /* ==== Nothing to do ... */
    /* ... for an empty active block ... ==== */
    *ns = 0;
    *nd = 0;
    work[1] = 1.f;
    if (*ktop > *kbot)
    {
        return 0;
    }
    /* ... nor for an empty deflation window. ==== */
    if (*nw < 1)
    {
        return 0;
    }
    /* ==== Machine constants ==== */
    safmin = slamch_("SAFE MINIMUM");
    safmax = 1.f / safmin;
    slabad_(&safmin, &safmax);
    ulp = slamch_("PRECISION");
    smlnum = safmin * ((real) (*n) / ulp);
    /* ==== Setup deflation window ==== */
    /* Computing MIN */
    i__1 = *nw;
    i__2 = *kbot - *ktop + 1; // , expr subst
    jw = min(i__1,i__2);
    kwtop = *kbot - jw + 1;
    if (kwtop == *ktop)
    {
        s = 0.f;
    }
    else
    {
        s = h__[kwtop + (kwtop - 1) * h_dim1];
    }
    if (*kbot == kwtop)
    {
        /* ==== 1-by-1 deflation window: not much to do ==== */
        sr[kwtop] = h__[kwtop + kwtop * h_dim1];
        si[kwtop] = 0.f;
        *ns = 1;
        *nd = 0;
        /* Computing MAX */
        r__2 = smlnum;
        r__3 = ulp * (r__1 = h__[kwtop + kwtop * h_dim1], abs( r__1)); // , expr subst
        if (abs(s) <= max(r__2,r__3))
        {
            *ns = 0;
            *nd = 1;
            if (kwtop > *ktop)
            {
                h__[kwtop + (kwtop - 1) * h_dim1] = 0.f;
            }
        }
        work[1] = 1.f;
        return 0;
    }
    /* ==== Convert to spike-triangular form. (In case of a */
    /* . rare QR failure, this routine continues to do */
    /* . aggressive early deflation using that part of */
    /* . the deflation window that converged using INFQR */
    /* . here and there to keep track.) ==== */
    slacpy_("U", &jw, &jw, &h__[kwtop + kwtop * h_dim1], ldh, &t[t_offset], ldt);
    i__1 = jw - 1;
    i__2 = *ldh + 1;
    i__3 = *ldt + 1;
    scopy_(&i__1, &h__[kwtop + 1 + kwtop * h_dim1], &i__2, &t[t_dim1 + 2], & i__3);
    slaset_("A", &jw, &jw, &c_b12, &c_b13, &v[v_offset], ldv);
    slahqr_(&c_true, &c_true, &jw, &c__1, &jw, &t[t_offset], ldt, &sr[kwtop], &si[kwtop], &c__1, &jw, &v[v_offset], ldv, &infqr);
    /* ==== STREXC needs a clean margin near the diagonal ==== */
    i__1 = jw - 3;
    for (j = 1;
            j <= i__1;
            ++j)
    {
        t[j + 2 + j * t_dim1] = 0.f;
        t[j + 3 + j * t_dim1] = 0.f;
        /* L10: */
    }
    if (jw > 2)
    {
        t[jw + (jw - 2) * t_dim1] = 0.f;
    }
    /* ==== Deflation detection loop ==== */
    *ns = jw;
    ilst = infqr + 1;
L20:
    if (ilst <= *ns)
    {
        if (*ns == 1)
        {
            bulge = FALSE_;
        }
        else
        {
            bulge = t[*ns + (*ns - 1) * t_dim1] != 0.f;
        }
        /* ==== Small spike tip test for deflation ==== */
        if (! bulge)
        {
            /* ==== Real eigenvalue ==== */
            foo = (r__1 = t[*ns + *ns * t_dim1], abs(r__1));
            if (foo == 0.f)
            {
                foo = abs(s);
            }
            /* Computing MAX */
            r__2 = smlnum;
            r__3 = ulp * foo; // , expr subst
            if ((r__1 = s * v[*ns * v_dim1 + 1], abs(r__1)) <= max(r__2,r__3))
            {
                /* ==== Deflatable ==== */
                --(*ns);
            }
            else
            {
                /* ==== Undeflatable. Move it up out of the way. */
                /* . (STREXC can not fail in this case.) ==== */
                ifst = *ns;
                strexc_("V", &jw, &t[t_offset], ldt, &v[v_offset], ldv, &ifst, &ilst, &work[1], &info);
                ++ilst;
            }
        }
        else
        {
            /* ==== Complex conjugate pair ==== */
            foo = (r__3 = t[*ns + *ns * t_dim1], abs(r__3)) + sqrt((r__1 = t[* ns + (*ns - 1) * t_dim1], abs(r__1))) * sqrt((r__2 = t[* ns - 1 + *ns * t_dim1], abs(r__2)));
            if (foo == 0.f)
            {
                foo = abs(s);
            }
            /* Computing MAX */
            r__3 = (r__1 = s * v[*ns * v_dim1 + 1], abs(r__1));
            r__4 = (r__2 = s * v[(*ns - 1) * v_dim1 + 1], abs(r__2)); // , expr subst
            /* Computing MAX */
            r__5 = smlnum;
            r__6 = ulp * foo; // , expr subst
            if (max(r__3,r__4) <= max(r__5,r__6))
            {
                /* ==== Deflatable ==== */
                *ns += -2;
            }
            else
            {
                /* ==== Undeflatable. Move them up out of the way. */
                /* . Fortunately, STREXC does the right thing with */
                /* . ILST in case of a rare exchange failure. ==== */
                ifst = *ns;
                strexc_("V", &jw, &t[t_offset], ldt, &v[v_offset], ldv, &ifst, &ilst, &work[1], &info);
                ilst += 2;
            }
        }
        /* ==== End deflation detection loop ==== */
        goto L20;
    }
    /* ==== Return to Hessenberg form ==== */
    if (*ns == 0)
    {
        s = 0.f;
    }
    if (*ns < jw)
    {
        /* ==== sorting diagonal blocks of T improves accuracy for */
        /* . graded matrices. Bubble sort deals well with */
        /* . exchange failures. ==== */
        sorted = FALSE_;
        i__ = *ns + 1;
L30:
        if (sorted)
        {
            goto L50;
        }
        sorted = TRUE_;
        kend = i__ - 1;
        i__ = infqr + 1;
        if (i__ == *ns)
        {
            k = i__ + 1;
        }
        else if (t[i__ + 1 + i__ * t_dim1] == 0.f)
        {
            k = i__ + 1;
        }
        else
        {
            k = i__ + 2;
        }
L40:
        if (k <= kend)
        {
            if (k == i__ + 1)
            {
                evi = (r__1 = t[i__ + i__ * t_dim1], abs(r__1));
            }
            else
            {
                evi = (r__3 = t[i__ + i__ * t_dim1], abs(r__3)) + sqrt((r__1 = t[i__ + 1 + i__ * t_dim1], abs(r__1))) * sqrt((r__2 = t[i__ + (i__ + 1) * t_dim1], abs(r__2)));
            }
            if (k == kend)
            {
                evk = (r__1 = t[k + k * t_dim1], abs(r__1));
            }
            else if (t[k + 1 + k * t_dim1] == 0.f)
            {
                evk = (r__1 = t[k + k * t_dim1], abs(r__1));
            }
            else
            {
                evk = (r__3 = t[k + k * t_dim1], abs(r__3)) + sqrt((r__1 = t[ k + 1 + k * t_dim1], abs(r__1))) * sqrt((r__2 = t[k + (k + 1) * t_dim1], abs(r__2)));
            }
            if (evi >= evk)
            {
                i__ = k;
            }
            else
            {
                sorted = FALSE_;
                ifst = i__;
                ilst = k;
                strexc_("V", &jw, &t[t_offset], ldt, &v[v_offset], ldv, &ifst, &ilst, &work[1], &info);
                if (info == 0)
                {
                    i__ = ilst;
                }
                else
                {
                    i__ = k;
                }
            }
            if (i__ == kend)
            {
                k = i__ + 1;
            }
            else if (t[i__ + 1 + i__ * t_dim1] == 0.f)
            {
                k = i__ + 1;
            }
            else
            {
                k = i__ + 2;
            }
            goto L40;
        }
        goto L30;
L50:
        ;
    }
    /* ==== Restore shift/eigenvalue array from T ==== */
    i__ = jw;
L60:
    if (i__ >= infqr + 1)
    {
        if (i__ == infqr + 1)
        {
            sr[kwtop + i__ - 1] = t[i__ + i__ * t_dim1];
            si[kwtop + i__ - 1] = 0.f;
            --i__;
        }
        else if (t[i__ + (i__ - 1) * t_dim1] == 0.f)
        {
            sr[kwtop + i__ - 1] = t[i__ + i__ * t_dim1];
            si[kwtop + i__ - 1] = 0.f;
            --i__;
        }
        else
        {
            aa = t[i__ - 1 + (i__ - 1) * t_dim1];
            cc = t[i__ + (i__ - 1) * t_dim1];
            bb = t[i__ - 1 + i__ * t_dim1];
            dd = t[i__ + i__ * t_dim1];
            slanv2_(&aa, &bb, &cc, &dd, &sr[kwtop + i__ - 2], &si[kwtop + i__ - 2], &sr[kwtop + i__ - 1], &si[kwtop + i__ - 1], &cs, & sn);
            i__ += -2;
        }
        goto L60;
    }
    if (*ns < jw || s == 0.f)
    {
        if (*ns > 1 && s != 0.f)
        {
            /* ==== Reflect spike back into lower triangle ==== */
            scopy_(ns, &v[v_offset], ldv, &work[1], &c__1);
            beta = work[1];
            slarfg_(ns, &beta, &work[2], &c__1, &tau);
            work[1] = 1.f;
            i__1 = jw - 2;
            i__2 = jw - 2;
            slaset_("L", &i__1, &i__2, &c_b12, &c_b12, &t[t_dim1 + 3], ldt);
            slarf_("L", ns, &jw, &work[1], &c__1, &tau, &t[t_offset], ldt, & work[jw + 1]);
            slarf_("R", ns, ns, &work[1], &c__1, &tau, &t[t_offset], ldt, & work[jw + 1]);
            slarf_("R", &jw, ns, &work[1], &c__1, &tau, &v[v_offset], ldv, & work[jw + 1]);
            i__1 = *lwork - jw;
            sgehrd_(&jw, &c__1, ns, &t[t_offset], ldt, &work[1], &work[jw + 1] , &i__1, &info);
        }
        /* ==== Copy updated reduced window into place ==== */
        if (kwtop > 1)
        {
            h__[kwtop + (kwtop - 1) * h_dim1] = s * v[v_dim1 + 1];
        }
        slacpy_("U", &jw, &jw, &t[t_offset], ldt, &h__[kwtop + kwtop * h_dim1] , ldh);
        i__1 = jw - 1;
        i__2 = *ldt + 1;
        i__3 = *ldh + 1;
        scopy_(&i__1, &t[t_dim1 + 2], &i__2, &h__[kwtop + 1 + kwtop * h_dim1], &i__3);
        /* ==== Accumulate orthogonal matrix in order update */
        /* . H and Z, if requested. ==== */
        if (*ns > 1 && s != 0.f)
        {
            i__1 = *lwork - jw;
            sormhr_("R", "N", &jw, ns, &c__1, ns, &t[t_offset], ldt, &work[1], &v[v_offset], ldv, &work[jw + 1], &i__1, &info);
        }
        /* ==== Update vertical slab in H ==== */
        if (*wantt)
        {
            ltop = 1;
        }
        else
        {
            ltop = *ktop;
        }
        i__1 = kwtop - 1;
        i__2 = *nv;
        for (krow = ltop;
                i__2 < 0 ? krow >= i__1 : krow <= i__1;
                krow += i__2)
        {
            /* Computing MIN */
            i__3 = *nv;
            i__4 = kwtop - krow; // , expr subst
            kln = min(i__3,i__4);
            sgemm_("N", "N", &kln, &jw, &jw, &c_b13, &h__[krow + kwtop * h_dim1], ldh, &v[v_offset], ldv, &c_b12, &wv[wv_offset], ldwv);
            slacpy_("A", &kln, &jw, &wv[wv_offset], ldwv, &h__[krow + kwtop * h_dim1], ldh);
            /* L70: */
        }
        /* ==== Update horizontal slab in H ==== */
        if (*wantt)
        {
            i__2 = *n;
            i__1 = *nh;
            for (kcol = *kbot + 1;
                    i__1 < 0 ? kcol >= i__2 : kcol <= i__2;
                    kcol += i__1)
            {
                /* Computing MIN */
                i__3 = *nh;
                i__4 = *n - kcol + 1; // , expr subst
                kln = min(i__3,i__4);
                sgemm_("C", "N", &jw, &kln, &jw, &c_b13, &v[v_offset], ldv, & h__[kwtop + kcol * h_dim1], ldh, &c_b12, &t[t_offset], ldt);
                slacpy_("A", &jw, &kln, &t[t_offset], ldt, &h__[kwtop + kcol * h_dim1], ldh);
                /* L80: */
            }
        }
        /* ==== Update vertical slab in Z ==== */
        if (*wantz)
        {
            i__1 = *ihiz;
            i__2 = *nv;
            for (krow = *iloz;
                    i__2 < 0 ? krow >= i__1 : krow <= i__1;
                    krow += i__2)
            {
                /* Computing MIN */
                i__3 = *nv;
                i__4 = *ihiz - krow + 1; // , expr subst
                kln = min(i__3,i__4);
                sgemm_("N", "N", &kln, &jw, &jw, &c_b13, &z__[krow + kwtop * z_dim1], ldz, &v[v_offset], ldv, &c_b12, &wv[ wv_offset], ldwv);
                slacpy_("A", &kln, &jw, &wv[wv_offset], ldwv, &z__[krow + kwtop * z_dim1], ldz);
                /* L90: */
            }
        }
    }
    /* ==== Return the number of deflations ... ==== */
    *nd = jw - *ns;
    /* ==== ... and the number of shifts. (Subtracting */
    /* . INFQR from the spike length takes care */
    /* . of the case of a rare QR failure while */
    /* . calculating eigenvalues of the deflation */
    /* . window.) ==== */
    *ns -= infqr;
    /* ==== Return optimal workspace. ==== */
    work[1] = (real) lwkopt;
    /* ==== End of SLAQR2 ==== */
    return 0;
}
Esempio n. 23
0
/* Subroutine */ int sgebd2_(integer *m, integer *n, real *a, integer *lda, 
	real *d__, real *e, real *tauq, real *taup, real *work, integer *info)
{
    /* System generated locals */
    integer a_dim1, a_offset, i__1, i__2, i__3;

    /* Local variables */
    integer i__;
    extern /* Subroutine */ int slarf_(char *, integer *, integer *, real *, 
	    integer *, real *, real *, integer *, real *), xerbla_(
	    char *, integer *), slarfg_(integer *, real *, real *, 
	    integer *, real *);


/*  -- LAPACK routine (version 3.2) -- */
/*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/*     November 2006 */

/*     .. Scalar Arguments .. */
/*     .. */
/*     .. Array Arguments .. */
/*     .. */

/*  Purpose */
/*  ======= */

/*  SGEBD2 reduces a real general m by n matrix A to upper or lower */
/*  bidiagonal form B by an orthogonal transformation: Q' * A * P = B. */

/*  If m >= n, B is upper bidiagonal; if m < n, B is lower bidiagonal. */

/*  Arguments */
/*  ========= */

/*  M       (input) INTEGER */
/*          The number of rows in the matrix A.  M >= 0. */

/*  N       (input) INTEGER */
/*          The number of columns in the matrix A.  N >= 0. */

/*  A       (input/output) REAL array, dimension (LDA,N) */
/*          On entry, the m by n general matrix to be reduced. */
/*          On exit, */
/*          if m >= n, the diagonal and the first superdiagonal are */
/*            overwritten with the upper bidiagonal matrix B; the */
/*            elements below the diagonal, with the array TAUQ, represent */
/*            the orthogonal matrix Q as a product of elementary */
/*            reflectors, and the elements above the first superdiagonal, */
/*            with the array TAUP, represent the orthogonal matrix P as */
/*            a product of elementary reflectors; */
/*          if m < n, the diagonal and the first subdiagonal are */
/*            overwritten with the lower bidiagonal matrix B; the */
/*            elements below the first subdiagonal, with the array TAUQ, */
/*            represent the orthogonal matrix Q as a product of */
/*            elementary reflectors, and the elements above the diagonal, */
/*            with the array TAUP, represent the orthogonal matrix P as */
/*            a product of elementary reflectors. */
/*          See Further Details. */

/*  LDA     (input) INTEGER */
/*          The leading dimension of the array A.  LDA >= max(1,M). */

/*  D       (output) REAL array, dimension (min(M,N)) */
/*          The diagonal elements of the bidiagonal matrix B: */
/*          D(i) = A(i,i). */

/*  E       (output) REAL array, dimension (min(M,N)-1) */
/*          The off-diagonal elements of the bidiagonal matrix B: */
/*          if m >= n, E(i) = A(i,i+1) for i = 1,2,...,n-1; */
/*          if m < n, E(i) = A(i+1,i) for i = 1,2,...,m-1. */

/*  TAUQ    (output) REAL array dimension (min(M,N)) */
/*          The scalar factors of the elementary reflectors which */
/*          represent the orthogonal matrix Q. See Further Details. */

/*  TAUP    (output) REAL array, dimension (min(M,N)) */
/*          The scalar factors of the elementary reflectors which */
/*          represent the orthogonal matrix P. See Further Details. */

/*  WORK    (workspace) REAL array, dimension (max(M,N)) */

/*  INFO    (output) INTEGER */
/*          = 0: successful exit. */
/*          < 0: if INFO = -i, the i-th argument had an illegal value. */

/*  Further Details */
/*  =============== */

/*  The matrices Q and P are represented as products of elementary */
/*  reflectors: */

/*  If m >= n, */

/*     Q = H(1) H(2) . . . H(n)  and  P = G(1) G(2) . . . G(n-1) */

/*  Each H(i) and G(i) has the form: */

/*     H(i) = I - tauq * v * v'  and G(i) = I - taup * u * u' */

/*  where tauq and taup are real scalars, and v and u are real vectors; */
/*  v(1:i-1) = 0, v(i) = 1, and v(i+1:m) is stored on exit in A(i+1:m,i); */
/*  u(1:i) = 0, u(i+1) = 1, and u(i+2:n) is stored on exit in A(i,i+2:n); */
/*  tauq is stored in TAUQ(i) and taup in TAUP(i). */

/*  If m < n, */

/*     Q = H(1) H(2) . . . H(m-1)  and  P = G(1) G(2) . . . G(m) */

/*  Each H(i) and G(i) has the form: */

/*     H(i) = I - tauq * v * v'  and G(i) = I - taup * u * u' */

/*  where tauq and taup are real scalars, and v and u are real vectors; */
/*  v(1:i) = 0, v(i+1) = 1, and v(i+2:m) is stored on exit in A(i+2:m,i); */
/*  u(1:i-1) = 0, u(i) = 1, and u(i+1:n) is stored on exit in A(i,i+1:n); */
/*  tauq is stored in TAUQ(i) and taup in TAUP(i). */

/*  The contents of A on exit are illustrated by the following examples: */

/*  m = 6 and n = 5 (m > n):          m = 5 and n = 6 (m < n): */

/*    (  d   e   u1  u1  u1 )           (  d   u1  u1  u1  u1  u1 ) */
/*    (  v1  d   e   u2  u2 )           (  e   d   u2  u2  u2  u2 ) */
/*    (  v1  v2  d   e   u3 )           (  v1  e   d   u3  u3  u3 ) */
/*    (  v1  v2  v3  d   e  )           (  v1  v2  e   d   u4  u4 ) */
/*    (  v1  v2  v3  v4  d  )           (  v1  v2  v3  e   d   u5 ) */
/*    (  v1  v2  v3  v4  v5 ) */

/*  where d and e denote diagonal and off-diagonal elements of B, vi */
/*  denotes an element of the vector defining H(i), and ui an element of */
/*  the vector defining G(i). */

/*  ===================================================================== */

/*     .. Parameters .. */
/*     .. */
/*     .. Local Scalars .. */
/*     .. */
/*     .. External Subroutines .. */
/*     .. */
/*     .. Intrinsic Functions .. */
/*     .. */
/*     .. Executable Statements .. */

/*     Test the input parameters */

    /* Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    --d__;
    --e;
    --tauq;
    --taup;
    --work;

    /* Function Body */
    *info = 0;
    if (*m < 0) {
	*info = -1;
    } else if (*n < 0) {
	*info = -2;
    } else if (*lda < max(1,*m)) {
	*info = -4;
    }
    if (*info < 0) {
	i__1 = -(*info);
	xerbla_("SGEBD2", &i__1);
	return 0;
    }

    if (*m >= *n) {

/*        Reduce to upper bidiagonal form */

	i__1 = *n;
	for (i__ = 1; i__ <= i__1; ++i__) {

/*           Generate elementary reflector H(i) to annihilate A(i+1:m,i) */

	    i__2 = *m - i__ + 1;
/* Computing MIN */
	    i__3 = i__ + 1;
	    slarfg_(&i__2, &a[i__ + i__ * a_dim1], &a[min(i__3, *m)+ i__ * 
		    a_dim1], &c__1, &tauq[i__]);
	    d__[i__] = a[i__ + i__ * a_dim1];
	    a[i__ + i__ * a_dim1] = 1.f;

/*           Apply H(i) to A(i:m,i+1:n) from the left */

	    if (i__ < *n) {
		i__2 = *m - i__ + 1;
		i__3 = *n - i__;
		slarf_("Left", &i__2, &i__3, &a[i__ + i__ * a_dim1], &c__1, &
			tauq[i__], &a[i__ + (i__ + 1) * a_dim1], lda, &work[1]
);
	    }
	    a[i__ + i__ * a_dim1] = d__[i__];

	    if (i__ < *n) {

/*              Generate elementary reflector G(i) to annihilate */
/*              A(i,i+2:n) */

		i__2 = *n - i__;
/* Computing MIN */
		i__3 = i__ + 2;
		slarfg_(&i__2, &a[i__ + (i__ + 1) * a_dim1], &a[i__ + min(
			i__3, *n)* a_dim1], lda, &taup[i__]);
		e[i__] = a[i__ + (i__ + 1) * a_dim1];
		a[i__ + (i__ + 1) * a_dim1] = 1.f;

/*              Apply G(i) to A(i+1:m,i+1:n) from the right */

		i__2 = *m - i__;
		i__3 = *n - i__;
		slarf_("Right", &i__2, &i__3, &a[i__ + (i__ + 1) * a_dim1], 
			lda, &taup[i__], &a[i__ + 1 + (i__ + 1) * a_dim1], 
			lda, &work[1]);
		a[i__ + (i__ + 1) * a_dim1] = e[i__];
	    } else {
		taup[i__] = 0.f;
	    }
/* L10: */
	}
    } else {

/*        Reduce to lower bidiagonal form */

	i__1 = *m;
	for (i__ = 1; i__ <= i__1; ++i__) {

/*           Generate elementary reflector G(i) to annihilate A(i,i+1:n) */

	    i__2 = *n - i__ + 1;
/* Computing MIN */
	    i__3 = i__ + 1;
	    slarfg_(&i__2, &a[i__ + i__ * a_dim1], &a[i__ + min(i__3, *n)* 
		    a_dim1], lda, &taup[i__]);
	    d__[i__] = a[i__ + i__ * a_dim1];
	    a[i__ + i__ * a_dim1] = 1.f;

/*           Apply G(i) to A(i+1:m,i:n) from the right */

	    if (i__ < *m) {
		i__2 = *m - i__;
		i__3 = *n - i__ + 1;
		slarf_("Right", &i__2, &i__3, &a[i__ + i__ * a_dim1], lda, &
			taup[i__], &a[i__ + 1 + i__ * a_dim1], lda, &work[1]);
	    }
	    a[i__ + i__ * a_dim1] = d__[i__];

	    if (i__ < *m) {

/*              Generate elementary reflector H(i) to annihilate */
/*              A(i+2:m,i) */

		i__2 = *m - i__;
/* Computing MIN */
		i__3 = i__ + 2;
		slarfg_(&i__2, &a[i__ + 1 + i__ * a_dim1], &a[min(i__3, *m)+ 
			i__ * a_dim1], &c__1, &tauq[i__]);
		e[i__] = a[i__ + 1 + i__ * a_dim1];
		a[i__ + 1 + i__ * a_dim1] = 1.f;

/*              Apply H(i) to A(i+1:m,i+1:n) from the left */

		i__2 = *m - i__;
		i__3 = *n - i__;
		slarf_("Left", &i__2, &i__3, &a[i__ + 1 + i__ * a_dim1], &
			c__1, &tauq[i__], &a[i__ + 1 + (i__ + 1) * a_dim1], 
			lda, &work[1]);
		a[i__ + 1 + i__ * a_dim1] = e[i__];
	    } else {
		tauq[i__] = 0.f;
	    }
/* L20: */
	}
    }
    return 0;

/*     End of SGEBD2 */

} /* sgebd2_ */
Esempio n. 24
0
/* Subroutine */ int sgeqr2_(integer *m, integer *n, real *a, integer *lda,
                             real *tau, real *work, integer *info)
{
    /* System generated locals */
    integer a_dim1, a_offset, i__1, i__2, i__3;

    /* Local variables */
    integer i__, k;
    real aii;
    extern /* Subroutine */ int slarf_(char *, integer *, integer *, real *,
                                       integer *, real *, real *, integer *, real *), xerbla_(
                                           char *, integer *), slarfp_(integer *, real *, real *,
                                                   integer *, real *);


    /*  -- LAPACK routine (version 3.2) -- */
    /*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
    /*     November 2006 */

    /*     .. Scalar Arguments .. */
    /*     .. */
    /*     .. Array Arguments .. */
    /*     .. */

    /*  Purpose */
    /*  ======= */

    /*  SGEQR2 computes a QR factorization of a real m by n matrix A: */
    /*  A = Q * R. */

    /*  Arguments */
    /*  ========= */

    /*  M       (input) INTEGER */
    /*          The number of rows of the matrix A.  M >= 0. */

    /*  N       (input) INTEGER */
    /*          The number of columns of the matrix A.  N >= 0. */

    /*  A       (input/output) REAL array, dimension (LDA,N) */
    /*          On entry, the m by n matrix A. */
    /*          On exit, the elements on and above the diagonal of the array */
    /*          contain the min(m,n) by n upper trapezoidal matrix R (R is */
    /*          upper triangular if m >= n); the elements below the diagonal, */
    /*          with the array TAU, represent the orthogonal matrix Q as a */
    /*          product of elementary reflectors (see Further Details). */

    /*  LDA     (input) INTEGER */
    /*          The leading dimension of the array A.  LDA >= max(1,M). */

    /*  TAU     (output) REAL array, dimension (min(M,N)) */
    /*          The scalar factors of the elementary reflectors (see Further */
    /*          Details). */

    /*  WORK    (workspace) REAL array, dimension (N) */

    /*  INFO    (output) INTEGER */
    /*          = 0: successful exit */
    /*          < 0: if INFO = -i, the i-th argument had an illegal value */

    /*  Further Details */
    /*  =============== */

    /*  The matrix Q is represented as a product of elementary reflectors */

    /*     Q = H(1) H(2) . . . H(k), where k = min(m,n). */

    /*  Each H(i) has the form */

    /*     H(i) = I - tau * v * v' */

    /*  where tau is a real scalar, and v is a real vector with */
    /*  v(1:i-1) = 0 and v(i) = 1; v(i+1:m) is stored on exit in A(i+1:m,i), */
    /*  and tau in TAU(i). */

    /*  ===================================================================== */

    /*     .. Parameters .. */
    /*     .. */
    /*     .. Local Scalars .. */
    /*     .. */
    /*     .. External Subroutines .. */
    /*     .. */
    /*     .. Intrinsic Functions .. */
    /*     .. */
    /*     .. Executable Statements .. */

    /*     Test the input arguments */

    /* Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    --tau;
    --work;

    /* Function Body */
    *info = 0;
    if (*m < 0) {
        *info = -1;
    } else if (*n < 0) {
        *info = -2;
    } else if (*lda < max(1,*m)) {
        *info = -4;
    }
    if (*info != 0) {
        i__1 = -(*info);
        xerbla_("SGEQR2", &i__1);
        return 0;
    }

    k = min(*m,*n);

    i__1 = k;
    for (i__ = 1; i__ <= i__1; ++i__) {

        /*        Generate elementary reflector H(i) to annihilate A(i+1:m,i) */

        i__2 = *m - i__ + 1;
        /* Computing MIN */
        i__3 = i__ + 1;
        slarfp_(&i__2, &a[i__ + i__ * a_dim1], &a[min(i__3, *m)+ i__ * a_dim1]
                , &c__1, &tau[i__]);
        if (i__ < *n) {

            /*           Apply H(i) to A(i:m,i+1:n) from the left */

            aii = a[i__ + i__ * a_dim1];
            a[i__ + i__ * a_dim1] = 1.f;
            i__2 = *m - i__ + 1;
            i__3 = *n - i__;
            slarf_("Left", &i__2, &i__3, &a[i__ + i__ * a_dim1], &c__1, &tau[
                       i__], &a[i__ + (i__ + 1) * a_dim1], lda, &work[1]);
            a[i__ + i__ * a_dim1] = aii;
        }
        /* L10: */
    }
    return 0;

    /*     End of SGEQR2 */

} /* sgeqr2_ */
Esempio n. 25
0
/* Subroutine */ int sorgl2_(integer *m, integer *n, integer *k, real *a, 
	integer *lda, real *tau, real *work, integer *info)
{
/*  -- LAPACK routine (version 2.0) --   
       Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,   
       Courant Institute, Argonne National Lab, and Rice University   
       February 29, 1992   


    Purpose   
    =======   

    SORGL2 generates an m by n real matrix Q with orthonormal rows,   
    which is defined as the first m rows of a product of k elementary   
    reflectors of order n   

          Q  =  H(k) . . . H(2) H(1)   

    as returned by SGELQF.   

    Arguments   
    =========   

    M       (input) INTEGER   
            The number of rows of the matrix Q. M >= 0.   

    N       (input) INTEGER   
            The number of columns of the matrix Q. N >= M.   

    K       (input) INTEGER   
            The number of elementary reflectors whose product defines the 
  
            matrix Q. M >= K >= 0.   

    A       (input/output) REAL array, dimension (LDA,N)   
            On entry, the i-th row must contain the vector which defines 
  
            the elementary reflector H(i), for i = 1,2,...,k, as returned 
  
            by SGELQF in the first k rows of its array argument A.   
            On exit, the m-by-n matrix Q.   

    LDA     (input) INTEGER   
            The first dimension of the array A. LDA >= max(1,M).   

    TAU     (input) REAL array, dimension (K)   
            TAU(i) must contain the scalar factor of the elementary   
            reflector H(i), as returned by SGELQF.   

    WORK    (workspace) REAL array, dimension (M)   

    INFO    (output) INTEGER   
            = 0: successful exit   
            < 0: if INFO = -i, the i-th argument has an illegal value   

    ===================================================================== 
  


       Test the input arguments   

    
   Parameter adjustments   
       Function Body */
    /* System generated locals */
    integer a_dim1, a_offset, i__1, i__2;
    real r__1;
    /* Local variables */
    static integer i, j, l;
    extern /* Subroutine */ int sscal_(integer *, real *, real *, integer *), 
	    slarf_(char *, integer *, integer *, real *, integer *, real *, 
	    real *, integer *, real *), xerbla_(char *, integer *);


#define TAU(I) tau[(I)-1]
#define WORK(I) work[(I)-1]

#define A(I,J) a[(I)-1 + ((J)-1)* ( *lda)]

    *info = 0;
    if (*m < 0) {
	*info = -1;
    } else if (*n < *m) {
	*info = -2;
    } else if (*k < 0 || *k > *m) {
	*info = -3;
    } else if (*lda < max(1,*m)) {
	*info = -5;
    }
    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("SORGL2", &i__1);
	return 0;
    }

/*     Quick return if possible */

    if (*m <= 0) {
	return 0;
    }

    if (*k < *m) {

/*        Initialise rows k+1:m to rows of the unit matrix */

	i__1 = *n;
	for (j = 1; j <= *n; ++j) {
	    i__2 = *m;
	    for (l = *k + 1; l <= *m; ++l) {
		A(l,j) = 0.f;
/* L10: */
	    }
	    if (j > *k && j <= *m) {
		A(j,j) = 1.f;
	    }
/* L20: */
	}
    }

    for (i = *k; i >= 1; --i) {

/*        Apply H(i) to A(i:m,i:n) from the right */

	if (i < *n) {
	    if (i < *m) {
		A(i,i) = 1.f;
		i__1 = *m - i;
		i__2 = *n - i + 1;
		slarf_("Right", &i__1, &i__2, &A(i,i), lda, &TAU(i)
			, &A(i+1,i), lda, &WORK(1));
	    }
	    i__1 = *n - i;
	    r__1 = -(doublereal)TAU(i);
	    sscal_(&i__1, &r__1, &A(i,i+1), lda);
	}
	A(i,i) = 1.f - TAU(i);

/*        Set A(1:i-1,i) to zero */

	i__1 = i - 1;
	for (l = 1; l <= i-1; ++l) {
	    A(i,l) = 0.f;
/* L30: */
	}
/* L40: */
    }
    return 0;

/*     End of SORGL2 */

} /* sorgl2_ */
Esempio n. 26
0
/* Subroutine */ int sorgl2_(integer *m, integer *n, integer *k, real *a, 
	integer *lda, real *tau, real *work, integer *info)
{
    /* System generated locals */
    integer a_dim1, a_offset, i__1, i__2;
    real r__1;

    /* Local variables */
    integer i__, j, l;
    extern /* Subroutine */ int sscal_(integer *, real *, real *, integer *), 
	    slarf_(char *, integer *, integer *, real *, integer *, real *, 
	    real *, integer *, real *), xerbla_(char *, integer *);


/*  -- LAPACK routine (version 3.2) -- */
/*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/*     November 2006 */

/*     .. Scalar Arguments .. */
/*     .. */
/*     .. Array Arguments .. */
/*     .. */

/*  Purpose */
/*  ======= */

/*  SORGL2 generates an m by n real matrix Q with orthonormal rows, */
/*  which is defined as the first m rows of a product of k elementary */
/*  reflectors of order n */

/*        Q  =  H(k) . . . H(2) H(1) */

/*  as returned by SGELQF. */

/*  Arguments */
/*  ========= */

/*  M       (input) INTEGER */
/*          The number of rows of the matrix Q. M >= 0. */

/*  N       (input) INTEGER */
/*          The number of columns of the matrix Q. N >= M. */

/*  K       (input) INTEGER */
/*          The number of elementary reflectors whose product defines the */
/*          matrix Q. M >= K >= 0. */

/*  A       (input/output) REAL array, dimension (LDA,N) */
/*          On entry, the i-th row must contain the vector which defines */
/*          the elementary reflector H(i), for i = 1,2,...,k, as returned */
/*          by SGELQF in the first k rows of its array argument A. */
/*          On exit, the m-by-n matrix Q. */

/*  LDA     (input) INTEGER */
/*          The first dimension of the array A. LDA >= max(1,M). */

/*  TAU     (input) REAL array, dimension (K) */
/*          TAU(i) must contain the scalar factor of the elementary */
/*          reflector H(i), as returned by SGELQF. */

/*  WORK    (workspace) REAL array, dimension (M) */

/*  INFO    (output) INTEGER */
/*          = 0: successful exit */
/*          < 0: if INFO = -i, the i-th argument has an illegal value */

/*  ===================================================================== */

/*     .. Parameters .. */
/*     .. */
/*     .. Local Scalars .. */
/*     .. */
/*     .. External Subroutines .. */
/*     .. */
/*     .. Intrinsic Functions .. */
/*     .. */
/*     .. Executable Statements .. */

/*     Test the input arguments */

    /* Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    --tau;
    --work;

    /* Function Body */
    *info = 0;
    if (*m < 0) {
	*info = -1;
    } else if (*n < *m) {
	*info = -2;
    } else if (*k < 0 || *k > *m) {
	*info = -3;
    } else if (*lda < max(1,*m)) {
	*info = -5;
    }
    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("SORGL2", &i__1);
	return 0;
    }

/*     Quick return if possible */

    if (*m <= 0) {
	return 0;
    }

    if (*k < *m) {

/*        Initialise rows k+1:m to rows of the unit matrix */

	i__1 = *n;
	for (j = 1; j <= i__1; ++j) {
	    i__2 = *m;
	    for (l = *k + 1; l <= i__2; ++l) {
		a[l + j * a_dim1] = 0.f;
/* L10: */
	    }
	    if (j > *k && j <= *m) {
		a[j + j * a_dim1] = 1.f;
	    }
/* L20: */
	}
    }

    for (i__ = *k; i__ >= 1; --i__) {

/*        Apply H(i) to A(i:m,i:n) from the right */

	if (i__ < *n) {
	    if (i__ < *m) {
		a[i__ + i__ * a_dim1] = 1.f;
		i__1 = *m - i__;
		i__2 = *n - i__ + 1;
		slarf_("Right", &i__1, &i__2, &a[i__ + i__ * a_dim1], lda, &
			tau[i__], &a[i__ + 1 + i__ * a_dim1], lda, &work[1]);
	    }
	    i__1 = *n - i__;
	    r__1 = -tau[i__];
	    sscal_(&i__1, &r__1, &a[i__ + (i__ + 1) * a_dim1], lda);
	}
	a[i__ + i__ * a_dim1] = 1.f - tau[i__];

/*        Set A(i,1:i-1) to zero */

	i__1 = i__ - 1;
	for (l = 1; l <= i__1; ++l) {
	    a[i__ + l * a_dim1] = 0.f;
/* L30: */
	}
/* L40: */
    }
    return 0;

/*     End of SORGL2 */

} /* sorgl2_ */
Esempio n. 27
0
/* Subroutine */ int sorg2l_(integer *m, integer *n, integer *k, real *a, 
	integer *lda, real *tau, real *work, integer *info)
{
    /* System generated locals */
    integer a_dim1, a_offset, i__1, i__2, i__3;
    real r__1;

    /* Local variables */
    static integer i__, j, l, ii;
    extern /* Subroutine */ int sscal_(integer *, real *, real *, integer *), 
	    slarf_(char *, integer *, integer *, real *, integer *, real *, 
	    real *, integer *, real *, ftnlen), xerbla_(char *, integer *, 
	    ftnlen);


/*  -- LAPACK routine (version 3.0) -- */
/*     Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd., */
/*     Courant Institute, Argonne National Lab, and Rice University */
/*     February 29, 1992 */

/*     .. Scalar Arguments .. */
/*     .. */
/*     .. Array Arguments .. */
/*     .. */

/*  Purpose */
/*  ======= */

/*  SORG2L generates an m by n real matrix Q with orthonormal columns, */
/*  which is defined as the last n columns of a product of k elementary */
/*  reflectors of order m */

/*        Q  =  H(k) . . . H(2) H(1) */

/*  as returned by SGEQLF. */

/*  Arguments */
/*  ========= */

/*  M       (input) INTEGER */
/*          The number of rows of the matrix Q. M >= 0. */

/*  N       (input) INTEGER */
/*          The number of columns of the matrix Q. M >= N >= 0. */

/*  K       (input) INTEGER */
/*          The number of elementary reflectors whose product defines the */
/*          matrix Q. N >= K >= 0. */

/*  A       (input/output) REAL array, dimension (LDA,N) */
/*          On entry, the (n-k+i)-th column must contain the vector which */
/*          defines the elementary reflector H(i), for i = 1,2,...,k, as */
/*          returned by SGEQLF in the last k columns of its array */
/*          argument A. */
/*          On exit, the m by n matrix Q. */

/*  LDA     (input) INTEGER */
/*          The first dimension of the array A. LDA >= max(1,M). */

/*  TAU     (input) REAL array, dimension (K) */
/*          TAU(i) must contain the scalar factor of the elementary */
/*          reflector H(i), as returned by SGEQLF. */

/*  WORK    (workspace) REAL array, dimension (N) */

/*  INFO    (output) INTEGER */
/*          = 0: successful exit */
/*          < 0: if INFO = -i, the i-th argument has an illegal value */

/*  ===================================================================== */

/*     .. Parameters .. */
/*     .. */
/*     .. Local Scalars .. */
/*     .. */
/*     .. External Subroutines .. */
/*     .. */
/*     .. Intrinsic Functions .. */
/*     .. */
/*     .. Executable Statements .. */

/*     Test the input arguments */

    /* Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    --tau;
    --work;

    /* Function Body */
    *info = 0;
    if (*m < 0) {
	*info = -1;
    } else if (*n < 0 || *n > *m) {
	*info = -2;
    } else if (*k < 0 || *k > *n) {
	*info = -3;
    } else if (*lda < max(1,*m)) {
	*info = -5;
    }
    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("SORG2L", &i__1, (ftnlen)6);
	return 0;
    }

/*     Quick return if possible */

    if (*n <= 0) {
	return 0;
    }

/*     Initialise columns 1:n-k to columns of the unit matrix */

    i__1 = *n - *k;
    for (j = 1; j <= i__1; ++j) {
	i__2 = *m;
	for (l = 1; l <= i__2; ++l) {
	    a[l + j * a_dim1] = 0.f;
/* L10: */
	}
	a[*m - *n + j + j * a_dim1] = 1.f;
/* L20: */
    }

    i__1 = *k;
    for (i__ = 1; i__ <= i__1; ++i__) {
	ii = *n - *k + i__;

/*        Apply H(i) to A(1:m-k+i,1:n-k+i) from the left */

	a[*m - *n + ii + ii * a_dim1] = 1.f;
	i__2 = *m - *n + ii;
	i__3 = ii - 1;
	slarf_("Left", &i__2, &i__3, &a[ii * a_dim1 + 1], &c__1, &tau[i__], &
		a[a_offset], lda, &work[1], (ftnlen)4);
	i__2 = *m - *n + ii - 1;
	r__1 = -tau[i__];
	sscal_(&i__2, &r__1, &a[ii * a_dim1 + 1], &c__1);
	a[*m - *n + ii + ii * a_dim1] = 1.f - tau[i__];

/*        Set A(m-k+i+1:m,n-k+i) to zero */

	i__2 = *m;
	for (l = *m - *n + ii + 1; l <= i__2; ++l) {
	    a[l + ii * a_dim1] = 0.f;
/* L30: */
	}
/* L40: */
    }
    return 0;

/*     End of SORG2L */

} /* sorg2l_ */