Exemplo n.º 1
0
/* Subroutine */ int chbev_(char *jobz, char *uplo, integer *n, integer *kd, 
	complex *ab, integer *ldab, real *w, complex *z__, integer *ldz, 
	complex *work, real *rwork, integer *info)
{
/*  -- LAPACK driver routine (version 3.0) --   
       Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,   
       Courant Institute, Argonne National Lab, and Rice University   
       June 30, 1999   


    Purpose   
    =======   

    CHBEV computes all the eigenvalues and, optionally, eigenvectors of   
    a complex Hermitian band matrix A.   

    Arguments   
    =========   

    JOBZ    (input) CHARACTER*1   
            = 'N':  Compute eigenvalues only;   
            = 'V':  Compute eigenvalues and eigenvectors.   

    UPLO    (input) CHARACTER*1   
            = 'U':  Upper triangle of A is stored;   
            = 'L':  Lower triangle of A is stored.   

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

    KD      (input) INTEGER   
            The number of superdiagonals of the matrix A if UPLO = 'U',   
            or the number of subdiagonals if UPLO = 'L'.  KD >= 0.   

    AB      (input/output) COMPLEX array, dimension (LDAB, N)   
            On entry, the upper or lower triangle of the Hermitian band   
            matrix A, stored in the first KD+1 rows of the array.  The   
            j-th column of A is stored in the j-th column of the array AB   
            as follows:   
            if UPLO = 'U', AB(kd+1+i-j,j) = A(i,j) for max(1,j-kd)<=i<=j;   
            if UPLO = 'L', AB(1+i-j,j)    = A(i,j) for j<=i<=min(n,j+kd).   

            On exit, AB is overwritten by values generated during the   
            reduction to tridiagonal form.  If UPLO = 'U', the first   
            superdiagonal and the diagonal of the tridiagonal matrix T   
            are returned in rows KD and KD+1 of AB, and if UPLO = 'L',   
            the diagonal and first subdiagonal of T are returned in the   
            first two rows of AB.   

    LDAB    (input) INTEGER   
            The leading dimension of the array AB.  LDAB >= KD + 1.   

    W       (output) REAL array, dimension (N)   
            If INFO = 0, the eigenvalues in ascending order.   

    Z       (output) COMPLEX array, dimension (LDZ, N)   
            If JOBZ = 'V', then if INFO = 0, Z contains the orthonormal   
            eigenvectors of the matrix A, with the i-th column of Z   
            holding the eigenvector associated with W(i).   
            If JOBZ = 'N', then Z is not referenced.   

    LDZ     (input) INTEGER   
            The leading dimension of the array Z.  LDZ >= 1, and if   
            JOBZ = 'V', LDZ >= max(1,N).   

    WORK    (workspace) COMPLEX array, dimension (N)   

    RWORK   (workspace) REAL array, dimension (max(1,3*N-2))   

    INFO    (output) INTEGER   
            = 0:  successful exit.   
            < 0:  if INFO = -i, the i-th argument had an illegal value.   
            > 0:  if INFO = i, the algorithm failed to converge; i   
                  off-diagonal elements of an intermediate tridiagonal   
                  form did not converge to zero.   

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


       Test the input parameters.   

       Parameter adjustments */
    /* Table of constant values */
    static real c_b11 = 1.f;
    static integer c__1 = 1;
    
    /* System generated locals */
    integer ab_dim1, ab_offset, z_dim1, z_offset, i__1;
    real r__1;
    /* Builtin functions */
    double sqrt(doublereal);
    /* Local variables */
    static integer inde;
    static real anrm;
    static integer imax;
    static real rmin, rmax, sigma;
    extern logical lsame_(char *, char *);
    static integer iinfo;
    extern /* Subroutine */ int sscal_(integer *, real *, real *, integer *);
    static logical lower, wantz;
    extern doublereal clanhb_(char *, char *, integer *, integer *, complex *,
	     integer *, real *);
    static integer iscale;
    extern /* Subroutine */ int clascl_(char *, integer *, integer *, real *, 
	    real *, integer *, integer *, complex *, integer *, integer *), chbtrd_(char *, char *, integer *, integer *, complex *, 
	    integer *, real *, real *, complex *, integer *, complex *, 
	    integer *);
    extern doublereal slamch_(char *);
    static real safmin;
    extern /* Subroutine */ int xerbla_(char *, integer *);
    static real bignum;
    static integer indrwk;
    extern /* Subroutine */ int csteqr_(char *, integer *, real *, real *, 
	    complex *, integer *, real *, integer *), ssterf_(integer 
	    *, real *, real *, integer *);
    static real smlnum, eps;
#define z___subscr(a_1,a_2) (a_2)*z_dim1 + a_1
#define z___ref(a_1,a_2) z__[z___subscr(a_1,a_2)]
#define ab_subscr(a_1,a_2) (a_2)*ab_dim1 + a_1
#define ab_ref(a_1,a_2) ab[ab_subscr(a_1,a_2)]


    ab_dim1 = *ldab;
    ab_offset = 1 + ab_dim1 * 1;
    ab -= ab_offset;
    --w;
    z_dim1 = *ldz;
    z_offset = 1 + z_dim1 * 1;
    z__ -= z_offset;
    --work;
    --rwork;

    /* Function Body */
    wantz = lsame_(jobz, "V");
    lower = lsame_(uplo, "L");

    *info = 0;
    if (! (wantz || lsame_(jobz, "N"))) {
	*info = -1;
    } else if (! (lower || lsame_(uplo, "U"))) {
	*info = -2;
    } else if (*n < 0) {
	*info = -3;
    } else if (*kd < 0) {
	*info = -4;
    } else if (*ldab < *kd + 1) {
	*info = -6;
    } else if (*ldz < 1 || wantz && *ldz < *n) {
	*info = -9;
    }

    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("CHBEV ", &i__1);
	return 0;
    }

/*     Quick return if possible */

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

    if (*n == 1) {
	if (lower) {
	    i__1 = ab_subscr(1, 1);
	    w[1] = ab[i__1].r;
	} else {
	    i__1 = ab_subscr(*kd + 1, 1);
	    w[1] = ab[i__1].r;
	}
	if (wantz) {
	    i__1 = z___subscr(1, 1);
	    z__[i__1].r = 1.f, z__[i__1].i = 0.f;
	}
	return 0;
    }

/*     Get machine constants. */

    safmin = slamch_("Safe minimum");
    eps = slamch_("Precision");
    smlnum = safmin / eps;
    bignum = 1.f / smlnum;
    rmin = sqrt(smlnum);
    rmax = sqrt(bignum);

/*     Scale matrix to allowable range, if necessary. */

    anrm = clanhb_("M", uplo, n, kd, &ab[ab_offset], ldab, &rwork[1]);
    iscale = 0;
    if (anrm > 0.f && anrm < rmin) {
	iscale = 1;
	sigma = rmin / anrm;
    } else if (anrm > rmax) {
	iscale = 1;
	sigma = rmax / anrm;
    }
    if (iscale == 1) {
	if (lower) {
	    clascl_("B", kd, kd, &c_b11, &sigma, n, n, &ab[ab_offset], ldab, 
		    info);
	} else {
	    clascl_("Q", kd, kd, &c_b11, &sigma, n, n, &ab[ab_offset], ldab, 
		    info);
	}
    }

/*     Call CHBTRD to reduce Hermitian band matrix to tridiagonal form. */

    inde = 1;
    chbtrd_(jobz, uplo, n, kd, &ab[ab_offset], ldab, &w[1], &rwork[inde], &
	    z__[z_offset], ldz, &work[1], &iinfo);

/*     For eigenvalues only, call SSTERF.  For eigenvectors, call CSTEQR. */

    if (! wantz) {
	ssterf_(n, &w[1], &rwork[inde], info);
    } else {
	indrwk = inde + *n;
	csteqr_(jobz, n, &w[1], &rwork[inde], &z__[z_offset], ldz, &rwork[
		indrwk], info);
    }

/*     If matrix was scaled, then rescale eigenvalues appropriately. */

    if (iscale == 1) {
	if (*info == 0) {
	    imax = *n;
	} else {
	    imax = *info - 1;
	}
	r__1 = 1.f / sigma;
	sscal_(&imax, &r__1, &w[1], &c__1);
    }

    return 0;

/*     End of CHBEV */

} /* chbev_ */
Exemplo n.º 2
0
/* Subroutine */ int cdrvpb_(logical *dotype, integer *nn, integer *nval, 
	integer *nrhs, real *thresh, logical *tsterr, integer *nmax, complex *
	a, complex *afac, complex *asav, complex *b, complex *bsav, complex *
	x, complex *xact, real *s, complex *work, real *rwork, integer *nout)
{
    /* Initialized data */

    static integer iseedy[4] = { 1988,1989,1990,1991 };
    static char facts[1*3] = "F" "N" "E";
    static char equeds[1*2] = "N" "Y";

    /* Format strings */
    static char fmt_9999[] = "(1x,a6,\002, UPLO='\002,a1,\002', N =\002,i5"
	    ",\002, KD =\002,i5,\002, type \002,i1,\002, test(\002,i1,\002)"
	    "=\002,g12.5)";
    static char fmt_9997[] = "(1x,a6,\002( '\002,a1,\002', '\002,a1,\002',"
	    " \002,i5,\002, \002,i5,\002, ... ), EQUED='\002,a1,\002', type"
	    " \002,i1,\002, test(\002,i1,\002)=\002,g12.5)";
    static char fmt_9998[] = "(1x,a6,\002( '\002,a1,\002', '\002,a1,\002',"
	    " \002,i5,\002, \002,i5,\002, ... ), type \002,i1,\002, test(\002"
	    ",i1,\002)=\002,g12.5)";

    /* System generated locals */
    address a__1[2];
    integer i__1, i__2, i__3, i__4, i__5, i__6, i__7[2];
    char ch__1[2];

    /* Builtin functions */
    /* Subroutine */ int s_copy(char *, char *, ftnlen, ftnlen);
    integer s_wsfe(cilist *), do_fio(integer *, char *, ftnlen), e_wsfe(void);
    /* Subroutine */ int s_cat(char *, char **, integer *, integer *, ftnlen);

    /* Local variables */
    integer i__, k, n, i1, i2, k1, kd, nb, in, kl, iw, ku, nt, lda, ikd, nkd, 
	    ldab;
    char fact[1];
    integer ioff, mode, koff;
    real amax;
    char path[3];
    integer imat, info;
    char dist[1], uplo[1], type__[1];
    integer nrun, ifact;
    extern /* Subroutine */ int cget04_(integer *, integer *, complex *, 
	    integer *, complex *, integer *, real *, real *);
    integer nfail, iseed[4], nfact;
    extern /* Subroutine */ int cpbt01_(char *, integer *, integer *, complex 
	    *, integer *, complex *, integer *, real *, real *), 
	    cpbt02_(char *, integer *, integer *, integer *, complex *, 
	    integer *, complex *, integer *, complex *, integer *, real *, 
	    real *), cpbt05_(char *, integer *, integer *, integer *, 
	    complex *, integer *, complex *, integer *, complex *, integer *, 
	    complex *, integer *, real *, real *, real *);
    integer kdval[4];
    extern logical lsame_(char *, char *);
    char equed[1];
    integer nbmin;
    real rcond, roldc, scond;
    integer nimat;
    extern doublereal sget06_(real *, real *);
    real anorm;
    extern /* Subroutine */ int ccopy_(integer *, complex *, integer *, 
	    complex *, integer *), cpbsv_(char *, integer *, integer *, 
	    integer *, complex *, integer *, complex *, integer *, integer *);
    logical equil;
    extern /* Subroutine */ int cswap_(integer *, complex *, integer *, 
	    complex *, integer *);
    integer iuplo, izero, nerrs;
    logical zerot;
    char xtype[1];
    extern /* Subroutine */ int clatb4_(char *, integer *, integer *, integer 
	    *, char *, integer *, integer *, real *, integer *, real *, char *
), aladhd_(integer *, char *);
    extern doublereal clanhb_(char *, char *, integer *, integer *, complex *, 
	     integer *, real *), clange_(char *, integer *, 
	    integer *, complex *, integer *, real *);
    extern /* Subroutine */ int claqhb_(char *, integer *, integer *, complex 
	    *, integer *, real *, real *, real *, char *), 
	    alaerh_(char *, char *, integer *, integer *, char *, integer *, 
	    integer *, integer *, integer *, integer *, integer *, integer *, 
	    integer *, integer *), claipd_(integer *, 
	    complex *, integer *, integer *);
    logical prefac;
    real rcondc;
    logical nofact;
    char packit[1];
    integer iequed;
    extern /* Subroutine */ int clacpy_(char *, integer *, integer *, complex 
	    *, integer *, complex *, integer *), clarhs_(char *, char 
	    *, char *, char *, integer *, integer *, integer *, integer *, 
	    integer *, complex *, integer *, complex *, integer *, complex *, 
	    integer *, integer *, integer *), 
	    claset_(char *, integer *, integer *, complex *, complex *, 
	    complex *, integer *), cpbequ_(char *, integer *, integer 
	    *, complex *, integer *, real *, real *, real *, integer *), alasvm_(char *, integer *, integer *, integer *, integer 
	    *);
    real cndnum;
    extern /* Subroutine */ int clatms_(integer *, integer *, char *, integer 
	    *, char *, real *, integer *, real *, real *, integer *, integer *
, char *, complex *, integer *, complex *, integer *), cpbtrf_(char *, integer *, integer *, complex *, 
	    integer *, integer *);
    real ainvnm;
    extern /* Subroutine */ int cpbtrs_(char *, integer *, integer *, integer 
	    *, complex *, integer *, complex *, integer *, integer *),
	     xlaenv_(integer *, integer *), cpbsvx_(char *, char *, integer *, 
	     integer *, integer *, complex *, integer *, complex *, integer *, 
	     char *, real *, complex *, integer *, complex *, integer *, real 
	    *, real *, real *, complex *, real *, integer *), cerrvx_(char *, integer *);
    real result[6];

    /* Fortran I/O blocks */
    static cilist io___57 = { 0, 0, 0, fmt_9999, 0 };
    static cilist io___60 = { 0, 0, 0, fmt_9997, 0 };
    static cilist io___61 = { 0, 0, 0, fmt_9998, 0 };



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

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

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

/*  CDRVPB tests the driver routines CPBSV and -SVX. */

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

/*  DOTYPE  (input) LOGICAL array, dimension (NTYPES) */
/*          The matrix types to be used for testing.  Matrices of type j */
/*          (for 1 <= j <= NTYPES) are used for testing if DOTYPE(j) = */
/*          .TRUE.; if DOTYPE(j) = .FALSE., then type j is not used. */

/*  NN      (input) INTEGER */
/*          The number of values of N contained in the vector NVAL. */

/*  NVAL    (input) INTEGER array, dimension (NN) */
/*          The values of the matrix dimension N. */

/*  NRHS    (input) INTEGER */
/*          The number of right hand side vectors to be generated for */
/*          each linear system. */

/*  THRESH  (input) REAL */
/*          The threshold value for the test ratios.  A result is */
/*          included in the output file if RESULT >= THRESH.  To have */
/*          every test ratio printed, use THRESH = 0. */

/*  TSTERR  (input) LOGICAL */
/*          Flag that indicates whether error exits are to be tested. */

/*  NMAX    (input) INTEGER */
/*          The maximum value permitted for N, used in dimensioning the */
/*          work arrays. */

/*  A       (workspace) COMPLEX array, dimension (NMAX*NMAX) */

/*  AFAC    (workspace) COMPLEX array, dimension (NMAX*NMAX) */

/*  ASAV    (workspace) COMPLEX array, dimension (NMAX*NMAX) */

/*  B       (workspace) COMPLEX array, dimension (NMAX*NRHS) */

/*  BSAV    (workspace) COMPLEX array, dimension (NMAX*NRHS) */

/*  X       (workspace) COMPLEX array, dimension (NMAX*NRHS) */

/*  XACT    (workspace) COMPLEX array, dimension (NMAX*NRHS) */

/*  S       (workspace) REAL array, dimension (NMAX) */

/*  WORK    (workspace) COMPLEX array, dimension */
/*                      (NMAX*max(3,NRHS)) */

/*  RWORK   (workspace) REAL array, dimension (NMAX+2*NRHS) */

/*  NOUT    (input) INTEGER */
/*          The unit number for output. */

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

/*     .. Parameters .. */
/*     .. */
/*     .. Local Scalars .. */
/*     .. */
/*     .. Local Arrays .. */
/*     .. */
/*     .. External Functions .. */
/*     .. */
/*     .. External Subroutines .. */
/*     .. */
/*     .. Intrinsic Functions .. */
/*     .. */
/*     .. Scalars in Common .. */
/*     .. */
/*     .. Common blocks .. */
/*     .. */
/*     .. Data statements .. */
    /* Parameter adjustments */
    --rwork;
    --work;
    --s;
    --xact;
    --x;
    --bsav;
    --b;
    --asav;
    --afac;
    --a;
    --nval;
    --dotype;

    /* Function Body */
/*     .. */
/*     .. Executable Statements .. */

/*     Initialize constants and the random number seed. */

    s_copy(path, "Complex precision", (ftnlen)1, (ftnlen)17);
    s_copy(path + 1, "PB", (ftnlen)2, (ftnlen)2);
    nrun = 0;
    nfail = 0;
    nerrs = 0;
    for (i__ = 1; i__ <= 4; ++i__) {
	iseed[i__ - 1] = iseedy[i__ - 1];
/* L10: */
    }

/*     Test the error exits */

    if (*tsterr) {
	cerrvx_(path, nout);
    }
    infoc_1.infot = 0;
    kdval[0] = 0;

/*     Set the block size and minimum block size for testing. */

    nb = 1;
    nbmin = 2;
    xlaenv_(&c__1, &nb);
    xlaenv_(&c__2, &nbmin);

/*     Do for each value of N in NVAL */

    i__1 = *nn;
    for (in = 1; in <= i__1; ++in) {
	n = nval[in];
	lda = max(n,1);
	*(unsigned char *)xtype = 'N';

/*        Set limits on the number of loop iterations. */

/* Computing MAX */
	i__2 = 1, i__3 = min(n,4);
	nkd = max(i__2,i__3);
	nimat = 8;
	if (n == 0) {
	    nimat = 1;
	}

	kdval[1] = n + (n + 1) / 4;
	kdval[2] = (n * 3 - 1) / 4;
	kdval[3] = (n + 1) / 4;

	i__2 = nkd;
	for (ikd = 1; ikd <= i__2; ++ikd) {

/*           Do for KD = 0, (5*N+1)/4, (3N-1)/4, and (N+1)/4. This order */
/*           makes it easier to skip redundant values for small values */
/*           of N. */

	    kd = kdval[ikd - 1];
	    ldab = kd + 1;

/*           Do first for UPLO = 'U', then for UPLO = 'L' */

	    for (iuplo = 1; iuplo <= 2; ++iuplo) {
		koff = 1;
		if (iuplo == 1) {
		    *(unsigned char *)uplo = 'U';
		    *(unsigned char *)packit = 'Q';
/* Computing MAX */
		    i__3 = 1, i__4 = kd + 2 - n;
		    koff = max(i__3,i__4);
		} else {
		    *(unsigned char *)uplo = 'L';
		    *(unsigned char *)packit = 'B';
		}

		i__3 = nimat;
		for (imat = 1; imat <= i__3; ++imat) {

/*                 Do the tests only if DOTYPE( IMAT ) is true. */

		    if (! dotype[imat]) {
			goto L80;
		    }

/*                 Skip types 2, 3, or 4 if the matrix size is too small. */

		    zerot = imat >= 2 && imat <= 4;
		    if (zerot && n < imat - 1) {
			goto L80;
		    }

		    if (! zerot || ! dotype[1]) {

/*                    Set up parameters with CLATB4 and generate a test */
/*                    matrix with CLATMS. */

			clatb4_(path, &imat, &n, &n, type__, &kl, &ku, &anorm, 
				 &mode, &cndnum, dist);

			s_copy(srnamc_1.srnamt, "CLATMS", (ftnlen)6, (ftnlen)
				6);
			clatms_(&n, &n, dist, iseed, type__, &rwork[1], &mode, 
				 &cndnum, &anorm, &kd, &kd, packit, &a[koff], 
				&ldab, &work[1], &info);

/*                    Check error code from CLATMS. */

			if (info != 0) {
			    alaerh_(path, "CLATMS", &info, &c__0, uplo, &n, &
				    n, &c_n1, &c_n1, &c_n1, &imat, &nfail, &
				    nerrs, nout);
			    goto L80;
			}
		    } else if (izero > 0) {

/*                    Use the same matrix for types 3 and 4 as for type */
/*                    2 by copying back the zeroed out column, */

			iw = (lda << 1) + 1;
			if (iuplo == 1) {
			    ioff = (izero - 1) * ldab + kd + 1;
			    i__4 = izero - i1;
			    ccopy_(&i__4, &work[iw], &c__1, &a[ioff - izero + 
				    i1], &c__1);
			    iw = iw + izero - i1;
			    i__4 = i2 - izero + 1;
/* Computing MAX */
			    i__6 = ldab - 1;
			    i__5 = max(i__6,1);
			    ccopy_(&i__4, &work[iw], &c__1, &a[ioff], &i__5);
			} else {
			    ioff = (i1 - 1) * ldab + 1;
			    i__4 = izero - i1;
/* Computing MAX */
			    i__6 = ldab - 1;
			    i__5 = max(i__6,1);
			    ccopy_(&i__4, &work[iw], &c__1, &a[ioff + izero - 
				    i1], &i__5);
			    ioff = (izero - 1) * ldab + 1;
			    iw = iw + izero - i1;
			    i__4 = i2 - izero + 1;
			    ccopy_(&i__4, &work[iw], &c__1, &a[ioff], &c__1);
			}
		    }

/*                 For types 2-4, zero one row and column of the matrix */
/*                 to test that INFO is returned correctly. */

		    izero = 0;
		    if (zerot) {
			if (imat == 2) {
			    izero = 1;
			} else if (imat == 3) {
			    izero = n;
			} else {
			    izero = n / 2 + 1;
			}

/*                    Save the zeroed out row and column in WORK(*,3) */

			iw = lda << 1;
/* Computing MIN */
			i__5 = (kd << 1) + 1;
			i__4 = min(i__5,n);
			for (i__ = 1; i__ <= i__4; ++i__) {
			    i__5 = iw + i__;
			    work[i__5].r = 0.f, work[i__5].i = 0.f;
/* L20: */
			}
			++iw;
/* Computing MAX */
			i__4 = izero - kd;
			i1 = max(i__4,1);
/* Computing MIN */
			i__4 = izero + kd;
			i2 = min(i__4,n);

			if (iuplo == 1) {
			    ioff = (izero - 1) * ldab + kd + 1;
			    i__4 = izero - i1;
			    cswap_(&i__4, &a[ioff - izero + i1], &c__1, &work[
				    iw], &c__1);
			    iw = iw + izero - i1;
			    i__4 = i2 - izero + 1;
/* Computing MAX */
			    i__6 = ldab - 1;
			    i__5 = max(i__6,1);
			    cswap_(&i__4, &a[ioff], &i__5, &work[iw], &c__1);
			} else {
			    ioff = (i1 - 1) * ldab + 1;
			    i__4 = izero - i1;
/* Computing MAX */
			    i__6 = ldab - 1;
			    i__5 = max(i__6,1);
			    cswap_(&i__4, &a[ioff + izero - i1], &i__5, &work[
				    iw], &c__1);
			    ioff = (izero - 1) * ldab + 1;
			    iw = iw + izero - i1;
			    i__4 = i2 - izero + 1;
			    cswap_(&i__4, &a[ioff], &c__1, &work[iw], &c__1);
			}
		    }

/*                 Set the imaginary part of the diagonals. */

		    if (iuplo == 1) {
			claipd_(&n, &a[kd + 1], &ldab, &c__0);
		    } else {
			claipd_(&n, &a[1], &ldab, &c__0);
		    }

/*                 Save a copy of the matrix A in ASAV. */

		    i__4 = kd + 1;
		    clacpy_("Full", &i__4, &n, &a[1], &ldab, &asav[1], &ldab);

		    for (iequed = 1; iequed <= 2; ++iequed) {
			*(unsigned char *)equed = *(unsigned char *)&equeds[
				iequed - 1];
			if (iequed == 1) {
			    nfact = 3;
			} else {
			    nfact = 1;
			}

			i__4 = nfact;
			for (ifact = 1; ifact <= i__4; ++ifact) {
			    *(unsigned char *)fact = *(unsigned char *)&facts[
				    ifact - 1];
			    prefac = lsame_(fact, "F");
			    nofact = lsame_(fact, "N");
			    equil = lsame_(fact, "E");

			    if (zerot) {
				if (prefac) {
				    goto L60;
				}
				rcondc = 0.f;

			    } else if (! lsame_(fact, "N")) {

/*                          Compute the condition number for comparison */
/*                          with the value returned by CPBSVX (FACT = */
/*                          'N' reuses the condition number from the */
/*                          previous iteration with FACT = 'F'). */

				i__5 = kd + 1;
				clacpy_("Full", &i__5, &n, &asav[1], &ldab, &
					afac[1], &ldab);
				if (equil || iequed > 1) {

/*                             Compute row and column scale factors to */
/*                             equilibrate the matrix A. */

				    cpbequ_(uplo, &n, &kd, &afac[1], &ldab, &
					    s[1], &scond, &amax, &info);
				    if (info == 0 && n > 0) {
					if (iequed > 1) {
					    scond = 0.f;
					}

/*                                Equilibrate the matrix. */

					claqhb_(uplo, &n, &kd, &afac[1], &
						ldab, &s[1], &scond, &amax, 
						equed);
				    }
				}

/*                          Save the condition number of the */
/*                          non-equilibrated system for use in CGET04. */

				if (equil) {
				    roldc = rcondc;
				}

/*                          Compute the 1-norm of A. */

				anorm = clanhb_("1", uplo, &n, &kd, &afac[1], 
					&ldab, &rwork[1]);

/*                          Factor the matrix A. */

				cpbtrf_(uplo, &n, &kd, &afac[1], &ldab, &info);

/*                          Form the inverse of A. */

				claset_("Full", &n, &n, &c_b47, &c_b48, &a[1], 
					 &lda);
				s_copy(srnamc_1.srnamt, "CPBTRS", (ftnlen)6, (
					ftnlen)6);
				cpbtrs_(uplo, &n, &kd, &n, &afac[1], &ldab, &
					a[1], &lda, &info);

/*                          Compute the 1-norm condition number of A. */

				ainvnm = clange_("1", &n, &n, &a[1], &lda, &
					rwork[1]);
				if (anorm <= 0.f || ainvnm <= 0.f) {
				    rcondc = 1.f;
				} else {
				    rcondc = 1.f / anorm / ainvnm;
				}
			    }

/*                       Restore the matrix A. */

			    i__5 = kd + 1;
			    clacpy_("Full", &i__5, &n, &asav[1], &ldab, &a[1], 
				     &ldab);

/*                       Form an exact solution and set the right hand */
/*                       side. */

			    s_copy(srnamc_1.srnamt, "CLARHS", (ftnlen)6, (
				    ftnlen)6);
			    clarhs_(path, xtype, uplo, " ", &n, &n, &kd, &kd, 
				    nrhs, &a[1], &ldab, &xact[1], &lda, &b[1], 
				     &lda, iseed, &info);
			    *(unsigned char *)xtype = 'C';
			    clacpy_("Full", &n, nrhs, &b[1], &lda, &bsav[1], &
				    lda);

			    if (nofact) {

/*                          --- Test CPBSV  --- */

/*                          Compute the L*L' or U'*U factorization of the */
/*                          matrix and solve the system. */

				i__5 = kd + 1;
				clacpy_("Full", &i__5, &n, &a[1], &ldab, &
					afac[1], &ldab);
				clacpy_("Full", &n, nrhs, &b[1], &lda, &x[1], 
					&lda);

				s_copy(srnamc_1.srnamt, "CPBSV ", (ftnlen)6, (
					ftnlen)6);
				cpbsv_(uplo, &n, &kd, nrhs, &afac[1], &ldab, &
					x[1], &lda, &info);

/*                          Check error code from CPBSV . */

				if (info != izero) {
				    alaerh_(path, "CPBSV ", &info, &izero, 
					    uplo, &n, &n, &kd, &kd, nrhs, &
					    imat, &nfail, &nerrs, nout);
				    goto L40;
				} else if (info != 0) {
				    goto L40;
				}

/*                          Reconstruct matrix from factors and compute */
/*                          residual. */

				cpbt01_(uplo, &n, &kd, &a[1], &ldab, &afac[1], 
					 &ldab, &rwork[1], result);

/*                          Compute residual of the computed solution. */

				clacpy_("Full", &n, nrhs, &b[1], &lda, &work[
					1], &lda);
				cpbt02_(uplo, &n, &kd, nrhs, &a[1], &ldab, &x[
					1], &lda, &work[1], &lda, &rwork[1], &
					result[1]);

/*                          Check solution from generated exact solution. */

				cget04_(&n, nrhs, &x[1], &lda, &xact[1], &lda, 
					 &rcondc, &result[2]);
				nt = 3;

/*                          Print information about the tests that did */
/*                          not pass the threshold. */

				i__5 = nt;
				for (k = 1; k <= i__5; ++k) {
				    if (result[k - 1] >= *thresh) {
					if (nfail == 0 && nerrs == 0) {
					    aladhd_(nout, path);
					}
					io___57.ciunit = *nout;
					s_wsfe(&io___57);
					do_fio(&c__1, "CPBSV ", (ftnlen)6);
					do_fio(&c__1, uplo, (ftnlen)1);
					do_fio(&c__1, (char *)&n, (ftnlen)
						sizeof(integer));
					do_fio(&c__1, (char *)&kd, (ftnlen)
						sizeof(integer));
					do_fio(&c__1, (char *)&imat, (ftnlen)
						sizeof(integer));
					do_fio(&c__1, (char *)&k, (ftnlen)
						sizeof(integer));
					do_fio(&c__1, (char *)&result[k - 1], 
						(ftnlen)sizeof(real));
					e_wsfe();
					++nfail;
				    }
/* L30: */
				}
				nrun += nt;
L40:
				;
			    }

/*                       --- Test CPBSVX --- */

			    if (! prefac) {
				i__5 = kd + 1;
				claset_("Full", &i__5, &n, &c_b47, &c_b47, &
					afac[1], &ldab);
			    }
			    claset_("Full", &n, nrhs, &c_b47, &c_b47, &x[1], &
				    lda);
			    if (iequed > 1 && n > 0) {

/*                          Equilibrate the matrix if FACT='F' and */
/*                          EQUED='Y' */

				claqhb_(uplo, &n, &kd, &a[1], &ldab, &s[1], &
					scond, &amax, equed);
			    }

/*                       Solve the system and compute the condition */
/*                       number and error bounds using CPBSVX. */

			    s_copy(srnamc_1.srnamt, "CPBSVX", (ftnlen)6, (
				    ftnlen)6);
			    cpbsvx_(fact, uplo, &n, &kd, nrhs, &a[1], &ldab, &
				    afac[1], &ldab, equed, &s[1], &b[1], &lda, 
				     &x[1], &lda, &rcond, &rwork[1], &rwork[*
				    nrhs + 1], &work[1], &rwork[(*nrhs << 1) 
				    + 1], &info);

/*                       Check the error code from CPBSVX. */

			    if (info != izero) {
/* Writing concatenation */
				i__7[0] = 1, a__1[0] = fact;
				i__7[1] = 1, a__1[1] = uplo;
				s_cat(ch__1, a__1, i__7, &c__2, (ftnlen)2);
				alaerh_(path, "CPBSVX", &info, &izero, ch__1, 
					&n, &n, &kd, &kd, nrhs, &imat, &nfail, 
					 &nerrs, nout);
				goto L60;
			    }

			    if (info == 0) {
				if (! prefac) {

/*                             Reconstruct matrix from factors and */
/*                             compute residual. */

				    cpbt01_(uplo, &n, &kd, &a[1], &ldab, &
					    afac[1], &ldab, &rwork[(*nrhs << 
					    1) + 1], result);
				    k1 = 1;
				} else {
				    k1 = 2;
				}

/*                          Compute residual of the computed solution. */

				clacpy_("Full", &n, nrhs, &bsav[1], &lda, &
					work[1], &lda);
				cpbt02_(uplo, &n, &kd, nrhs, &asav[1], &ldab, 
					&x[1], &lda, &work[1], &lda, &rwork[(*
					nrhs << 1) + 1], &result[1]);

/*                          Check solution from generated exact solution. */

				if (nofact || prefac && lsame_(equed, "N")) {
				    cget04_(&n, nrhs, &x[1], &lda, &xact[1], &
					    lda, &rcondc, &result[2]);
				} else {
				    cget04_(&n, nrhs, &x[1], &lda, &xact[1], &
					    lda, &roldc, &result[2]);
				}

/*                          Check the error bounds from iterative */
/*                          refinement. */

				cpbt05_(uplo, &n, &kd, nrhs, &asav[1], &ldab, 
					&b[1], &lda, &x[1], &lda, &xact[1], &
					lda, &rwork[1], &rwork[*nrhs + 1], &
					result[3]);
			    } else {
				k1 = 6;
			    }

/*                       Compare RCOND from CPBSVX with the computed */
/*                       value in RCONDC. */

			    result[5] = sget06_(&rcond, &rcondc);

/*                       Print information about the tests that did not */
/*                       pass the threshold. */

			    for (k = k1; k <= 6; ++k) {
				if (result[k - 1] >= *thresh) {
				    if (nfail == 0 && nerrs == 0) {
					aladhd_(nout, path);
				    }
				    if (prefac) {
					io___60.ciunit = *nout;
					s_wsfe(&io___60);
					do_fio(&c__1, "CPBSVX", (ftnlen)6);
					do_fio(&c__1, fact, (ftnlen)1);
					do_fio(&c__1, uplo, (ftnlen)1);
					do_fio(&c__1, (char *)&n, (ftnlen)
						sizeof(integer));
					do_fio(&c__1, (char *)&kd, (ftnlen)
						sizeof(integer));
					do_fio(&c__1, equed, (ftnlen)1);
					do_fio(&c__1, (char *)&imat, (ftnlen)
						sizeof(integer));
					do_fio(&c__1, (char *)&k, (ftnlen)
						sizeof(integer));
					do_fio(&c__1, (char *)&result[k - 1], 
						(ftnlen)sizeof(real));
					e_wsfe();
				    } else {
					io___61.ciunit = *nout;
					s_wsfe(&io___61);
					do_fio(&c__1, "CPBSVX", (ftnlen)6);
					do_fio(&c__1, fact, (ftnlen)1);
					do_fio(&c__1, uplo, (ftnlen)1);
					do_fio(&c__1, (char *)&n, (ftnlen)
						sizeof(integer));
					do_fio(&c__1, (char *)&kd, (ftnlen)
						sizeof(integer));
					do_fio(&c__1, (char *)&imat, (ftnlen)
						sizeof(integer));
					do_fio(&c__1, (char *)&k, (ftnlen)
						sizeof(integer));
					do_fio(&c__1, (char *)&result[k - 1], 
						(ftnlen)sizeof(real));
					e_wsfe();
				    }
				    ++nfail;
				}
/* L50: */
			    }
			    nrun = nrun + 7 - k1;
L60:
			    ;
			}
/* L70: */
		    }
L80:
		    ;
		}
/* L90: */
	    }
/* L100: */
	}
/* L110: */
    }

/*     Print a summary of the results. */

    alasvm_(path, nout, &nfail, &nrun, &nerrs);

    return 0;

/*     End of CDRVPB */

} /* cdrvpb_ */
Exemplo n.º 3
0
/* Subroutine */ int cpbt02_(char *uplo, integer *n, integer *kd, integer *
	nrhs, complex *a, integer *lda, complex *x, integer *ldx, complex *b, 
	integer *ldb, real *rwork, real *resid)
{
    /* System generated locals */
    integer a_dim1, a_offset, b_dim1, b_offset, x_dim1, x_offset, i__1;
    real r__1, r__2;
    complex q__1;

    /* Local variables */
    static integer j;
    extern /* Subroutine */ int chbmv_(char *, integer *, integer *, complex *
	    , complex *, integer *, complex *, integer *, complex *, complex *
	    , integer *);
    static real anorm, bnorm, xnorm;
    extern doublereal clanhb_(char *, char *, integer *, integer *, complex *,
	     integer *, real *), slamch_(char *), 
	    scasum_(integer *, complex *, integer *);
    static real eps;


#define b_subscr(a_1,a_2) (a_2)*b_dim1 + a_1
#define b_ref(a_1,a_2) b[b_subscr(a_1,a_2)]
#define x_subscr(a_1,a_2) (a_2)*x_dim1 + a_1
#define x_ref(a_1,a_2) x[x_subscr(a_1,a_2)]


/*  -- 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   
    =======   

    CPBT02 computes the residual for a solution of a Hermitian banded   
    system of equations  A*x = b:   
       RESID = norm( B - A*X ) / ( norm(A) * norm(X) * EPS)   
    where EPS is the machine precision.   

    Arguments   
    =========   

    UPLO    (input) CHARACTER*1   
            Specifies whether the upper or lower triangular part of the   
            Hermitian matrix A is stored:   
            = 'U':  Upper triangular   
            = 'L':  Lower triangular   

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

    KD      (input) INTEGER   
            The number of super-diagonals of the matrix A if UPLO = 'U',   
            or the number of sub-diagonals if UPLO = 'L'.  KD >= 0.   

    A       (input) COMPLEX array, dimension (LDA,N)   
            The original Hermitian band matrix A.  If UPLO = 'U', the   
            upper triangular part of A is stored as a band matrix; if   
            UPLO = 'L', the lower triangular part of A is stored.  The   
            columns of the appropriate triangle are stored in the columns   
            of A and the diagonals of the triangle are stored in the rows   
            of A.  See CPBTRF for further details.   

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

    X       (input) COMPLEX array, dimension (LDX,NRHS)   
            The computed solution vectors for the system of linear   
            equations.   

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

    B       (input/output) COMPLEX array, dimension (LDB,NRHS)   
            On entry, the right hand side vectors for the system of   
            linear equations.   
            On exit, B is overwritten with the difference B - A*X.   

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

    RWORK   (workspace) REAL array, dimension (N)   

    RESID   (output) REAL   
            The maximum over the number of right hand sides of   
            norm(B - A*X) / ( norm(A) * norm(X) * EPS ).   

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


       Quick exit if N = 0 or NRHS = 0.   

       Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1 * 1;
    a -= a_offset;
    x_dim1 = *ldx;
    x_offset = 1 + x_dim1 * 1;
    x -= x_offset;
    b_dim1 = *ldb;
    b_offset = 1 + b_dim1 * 1;
    b -= b_offset;
    --rwork;

    /* Function Body */
    if (*n <= 0 || *nrhs <= 0) {
	*resid = 0.f;
	return 0;
    }

/*     Exit with RESID = 1/EPS if ANORM = 0. */

    eps = slamch_("Epsilon");
    anorm = clanhb_("1", uplo, n, kd, &a[a_offset], lda, &rwork[1]);
    if (anorm <= 0.f) {
	*resid = 1.f / eps;
	return 0;
    }

/*     Compute  B - A*X */

    i__1 = *nrhs;
    for (j = 1; j <= i__1; ++j) {
	q__1.r = -1.f, q__1.i = 0.f;
	chbmv_(uplo, n, kd, &q__1, &a[a_offset], lda, &x_ref(1, j), &c__1, &
		c_b1, &b_ref(1, j), &c__1);
/* L10: */
    }

/*     Compute the maximum over the number of right hand sides of   
            norm( B - A*X ) / ( norm(A) * norm(X) * EPS ) */

    *resid = 0.f;
    i__1 = *nrhs;
    for (j = 1; j <= i__1; ++j) {
	bnorm = scasum_(n, &b_ref(1, j), &c__1);
	xnorm = scasum_(n, &x_ref(1, j), &c__1);
	if (xnorm <= 0.f) {
	    *resid = 1.f / eps;
	} else {
/* Computing MAX */
	    r__1 = *resid, r__2 = bnorm / anorm / xnorm / eps;
	    *resid = dmax(r__1,r__2);
	}
/* L20: */
    }

    return 0;

/*     End of CPBT02 */

} /* cpbt02_ */
Exemplo n.º 4
0
/* Subroutine */
int cpbsvx_(char *fact, char *uplo, integer *n, integer *kd, integer *nrhs, complex *ab, integer *ldab, complex *afb, integer * ldafb, char *equed, real *s, complex *b, integer *ldb, complex *x, integer *ldx, real *rcond, real *ferr, real *berr, complex *work, real *rwork, integer *info)
{
    /* System generated locals */
    integer ab_dim1, ab_offset, afb_dim1, afb_offset, b_dim1, b_offset, x_dim1, x_offset, i__1, i__2, i__3, i__4, i__5;
    real r__1, r__2;
    complex q__1;
    /* Local variables */
    integer i__, j, j1, j2;
    real amax, smin, smax;
    extern logical lsame_(char *, char *);
    real scond, anorm;
    extern /* Subroutine */
    int ccopy_(integer *, complex *, integer *, complex *, integer *);
    logical equil, rcequ, upper;
    extern real clanhb_(char *, char *, integer *, integer *, complex *, integer *, real *);
    extern /* Subroutine */
    int claqhb_(char *, integer *, integer *, complex *, integer *, real *, real *, real *, char *), cpbcon_(char *, integer *, integer *, complex *, integer *, real * , real *, complex *, real *, integer *);
    extern real slamch_(char *);
    logical nofact;
    extern /* Subroutine */
    int clacpy_(char *, integer *, integer *, complex *, integer *, complex *, integer *), xerbla_(char *, integer *), cpbequ_(char *, integer *, integer *, complex *, integer *, real *, real *, real *, integer *), cpbrfs_( char *, integer *, integer *, integer *, complex *, integer *, complex *, integer *, complex *, integer *, complex *, integer *, real *, real *, complex *, real *, integer *);
    real bignum;
    extern /* Subroutine */
    int cpbtrf_(char *, integer *, integer *, complex *, integer *, integer *);
    integer infequ;
    extern /* Subroutine */
    int cpbtrs_(char *, integer *, integer *, integer *, complex *, integer *, complex *, integer *, integer *);
    real smlnum;
    /* -- LAPACK driver routine (version 3.4.1) -- */
    /* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
    /* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
    /* April 2012 */
    /* .. Scalar Arguments .. */
    /* .. */
    /* .. Array Arguments .. */
    /* .. */
    /* ===================================================================== */
    /* .. Parameters .. */
    /* .. */
    /* .. Local Scalars .. */
    /* .. */
    /* .. External Functions .. */
    /* .. */
    /* .. External Subroutines .. */
    /* .. */
    /* .. Intrinsic Functions .. */
    /* .. */
    /* .. Executable Statements .. */
    /* Parameter adjustments */
    ab_dim1 = *ldab;
    ab_offset = 1 + ab_dim1;
    ab -= ab_offset;
    afb_dim1 = *ldafb;
    afb_offset = 1 + afb_dim1;
    afb -= afb_offset;
    --s;
    b_dim1 = *ldb;
    b_offset = 1 + b_dim1;
    b -= b_offset;
    x_dim1 = *ldx;
    x_offset = 1 + x_dim1;
    x -= x_offset;
    --ferr;
    --berr;
    --work;
    --rwork;
    /* Function Body */
    *info = 0;
    nofact = lsame_(fact, "N");
    equil = lsame_(fact, "E");
    upper = lsame_(uplo, "U");
    if (nofact || equil)
    {
        *(unsigned char *)equed = 'N';
        rcequ = FALSE_;
    }
    else
    {
        rcequ = lsame_(equed, "Y");
        smlnum = slamch_("Safe minimum");
        bignum = 1.f / smlnum;
    }
    /* Test the input parameters. */
    if (! nofact && ! equil && ! lsame_(fact, "F"))
    {
        *info = -1;
    }
    else if (! upper && ! lsame_(uplo, "L"))
    {
        *info = -2;
    }
    else if (*n < 0)
    {
        *info = -3;
    }
    else if (*kd < 0)
    {
        *info = -4;
    }
    else if (*nrhs < 0)
    {
        *info = -5;
    }
    else if (*ldab < *kd + 1)
    {
        *info = -7;
    }
    else if (*ldafb < *kd + 1)
    {
        *info = -9;
    }
    else if (lsame_(fact, "F") && ! (rcequ || lsame_( equed, "N")))
    {
        *info = -10;
    }
    else
    {
        if (rcequ)
        {
            smin = bignum;
            smax = 0.f;
            i__1 = *n;
            for (j = 1;
                    j <= i__1;
                    ++j)
            {
                /* Computing MIN */
                r__1 = smin;
                r__2 = s[j]; // , expr subst
                smin = min(r__1,r__2);
                /* Computing MAX */
                r__1 = smax;
                r__2 = s[j]; // , expr subst
                smax = max(r__1,r__2);
                /* L10: */
            }
            if (smin <= 0.f)
            {
                *info = -11;
            }
            else if (*n > 0)
            {
                scond = max(smin,smlnum) / min(smax,bignum);
            }
            else
            {
                scond = 1.f;
            }
        }
        if (*info == 0)
        {
            if (*ldb < max(1,*n))
            {
                *info = -13;
            }
            else if (*ldx < max(1,*n))
            {
                *info = -15;
            }
        }
    }
    if (*info != 0)
    {
        i__1 = -(*info);
        xerbla_("CPBSVX", &i__1);
        return 0;
    }
    if (equil)
    {
        /* Compute row and column scalings to equilibrate the matrix A. */
        cpbequ_(uplo, n, kd, &ab[ab_offset], ldab, &s[1], &scond, &amax, & infequ);
        if (infequ == 0)
        {
            /* Equilibrate the matrix. */
            claqhb_(uplo, n, kd, &ab[ab_offset], ldab, &s[1], &scond, &amax, equed);
            rcequ = lsame_(equed, "Y");
        }
    }
    /* Scale the right-hand side. */
    if (rcequ)
    {
        i__1 = *nrhs;
        for (j = 1;
                j <= i__1;
                ++j)
        {
            i__2 = *n;
            for (i__ = 1;
                    i__ <= i__2;
                    ++i__)
            {
                i__3 = i__ + j * b_dim1;
                i__4 = i__;
                i__5 = i__ + j * b_dim1;
                q__1.r = s[i__4] * b[i__5].r;
                q__1.i = s[i__4] * b[i__5].i; // , expr subst
                b[i__3].r = q__1.r;
                b[i__3].i = q__1.i; // , expr subst
                /* L20: */
            }
            /* L30: */
        }
    }
    if (nofact || equil)
    {
        /* Compute the Cholesky factorization A = U**H *U or A = L*L**H. */
        if (upper)
        {
            i__1 = *n;
            for (j = 1;
                    j <= i__1;
                    ++j)
            {
                /* Computing MAX */
                i__2 = j - *kd;
                j1 = max(i__2,1);
                i__2 = j - j1 + 1;
                ccopy_(&i__2, &ab[*kd + 1 - j + j1 + j * ab_dim1], &c__1, & afb[*kd + 1 - j + j1 + j * afb_dim1], &c__1);
                /* L40: */
            }
        }
        else
        {
            i__1 = *n;
            for (j = 1;
                    j <= i__1;
                    ++j)
            {
                /* Computing MIN */
                i__2 = j + *kd;
                j2 = min(i__2,*n);
                i__2 = j2 - j + 1;
                ccopy_(&i__2, &ab[j * ab_dim1 + 1], &c__1, &afb[j * afb_dim1 + 1], &c__1);
                /* L50: */
            }
        }
        cpbtrf_(uplo, n, kd, &afb[afb_offset], ldafb, info);
        /* Return if INFO is non-zero. */
        if (*info > 0)
        {
            *rcond = 0.f;
            return 0;
        }
    }
    /* Compute the norm of the matrix A. */
    anorm = clanhb_("1", uplo, n, kd, &ab[ab_offset], ldab, &rwork[1]);
    /* Compute the reciprocal of the condition number of A. */
    cpbcon_(uplo, n, kd, &afb[afb_offset], ldafb, &anorm, rcond, &work[1], & rwork[1], info);
    /* Compute the solution matrix X. */
    clacpy_("Full", n, nrhs, &b[b_offset], ldb, &x[x_offset], ldx);
    cpbtrs_(uplo, n, kd, nrhs, &afb[afb_offset], ldafb, &x[x_offset], ldx, info);
    /* Use iterative refinement to improve the computed solution and */
    /* compute error bounds and backward error estimates for it. */
    cpbrfs_(uplo, n, kd, nrhs, &ab[ab_offset], ldab, &afb[afb_offset], ldafb, &b[b_offset], ldb, &x[x_offset], ldx, &ferr[1], &berr[1], &work[1] , &rwork[1], info);
    /* Transform the solution matrix X to a solution of the original */
    /* system. */
    if (rcequ)
    {
        i__1 = *nrhs;
        for (j = 1;
                j <= i__1;
                ++j)
        {
            i__2 = *n;
            for (i__ = 1;
                    i__ <= i__2;
                    ++i__)
            {
                i__3 = i__ + j * x_dim1;
                i__4 = i__;
                i__5 = i__ + j * x_dim1;
                q__1.r = s[i__4] * x[i__5].r;
                q__1.i = s[i__4] * x[i__5].i; // , expr subst
                x[i__3].r = q__1.r;
                x[i__3].i = q__1.i; // , expr subst
                /* L60: */
            }
            /* L70: */
        }
        i__1 = *nrhs;
        for (j = 1;
                j <= i__1;
                ++j)
        {
            ferr[j] /= scond;
            /* L80: */
        }
    }
    /* Set INFO = N+1 if the matrix is singular to working precision. */
    if (*rcond < slamch_("Epsilon"))
    {
        *info = *n + 1;
    }
    return 0;
    /* End of CPBSVX */
}
Exemplo n.º 5
0
/* Subroutine */ int chbevx_(char *jobz, char *range, char *uplo, integer *n, 
	integer *kd, complex *ab, integer *ldab, complex *q, integer *ldq, 
	real *vl, real *vu, integer *il, integer *iu, real *abstol, integer *
	m, real *w, complex *z__, integer *ldz, complex *work, real *rwork, 
	integer *iwork, integer *ifail, integer *info)
{
    /* System generated locals */
    integer ab_dim1, ab_offset, q_dim1, q_offset, z_dim1, z_offset, i__1, 
	    i__2;
    real r__1, r__2;

    /* Local variables */
    integer i__, j, jj;
    real eps, vll, vuu, tmp1;
    integer indd, inde;
    real anrm;
    integer imax;
    real rmin, rmax;
    logical test;
    complex ctmp1;
    integer itmp1, indee;
    real sigma;
    integer iinfo;
    char order[1];
    logical lower;
    logical wantz;
    logical alleig, indeig;
    integer iscale, indibl;
    logical valeig;
    real safmin;
    real abstll, bignum;
    integer indiwk, indisp;
    integer indrwk, indwrk;
    integer nsplit;
    real smlnum;

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

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

/*  CHBEVX computes selected eigenvalues and, optionally, eigenvectors */
/*  of a complex Hermitian band matrix A.  Eigenvalues and eigenvectors */
/*  can be selected by specifying either a range of values or a range of */
/*  indices for the desired eigenvalues. */

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

/*  JOBZ    (input) CHARACTER*1 */
/*          = 'N':  Compute eigenvalues only; */
/*          = 'V':  Compute eigenvalues and eigenvectors. */

/*  RANGE   (input) CHARACTER*1 */
/*          = 'A': all eigenvalues will be found; */
/*          = 'V': all eigenvalues in the half-open interval (VL,VU] */
/*                 will be found; */
/*          = 'I': the IL-th through IU-th eigenvalues will be found. */

/*  UPLO    (input) CHARACTER*1 */
/*          = 'U':  Upper triangle of A is stored; */
/*          = 'L':  Lower triangle of A is stored. */

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

/*  KD      (input) INTEGER */
/*          The number of superdiagonals of the matrix A if UPLO = 'U', */
/*          or the number of subdiagonals if UPLO = 'L'.  KD >= 0. */

/*  AB      (input/output) COMPLEX array, dimension (LDAB, N) */
/*          On entry, the upper or lower triangle of the Hermitian band */
/*          matrix A, stored in the first KD+1 rows of the array.  The */
/*          j-th column of A is stored in the j-th column of the array AB */
/*          as follows: */
/*          if UPLO = 'U', AB(kd+1+i-j,j) = A(i,j) for max(1,j-kd)<=i<=j; */
/*          if UPLO = 'L', AB(1+i-j,j)    = A(i,j) for j<=i<=min(n,j+kd). */

/*          On exit, AB is overwritten by values generated during the */
/*          reduction to tridiagonal form. */

/*  LDAB    (input) INTEGER */
/*          The leading dimension of the array AB.  LDAB >= KD + 1. */

/*  Q       (output) COMPLEX array, dimension (LDQ, N) */
/*          If JOBZ = 'V', the N-by-N unitary matrix used in the */
/*                          reduction to tridiagonal form. */
/*          If JOBZ = 'N', the array Q is not referenced. */

/*  LDQ     (input) INTEGER */
/*          The leading dimension of the array Q.  If JOBZ = 'V', then */
/*          LDQ >= max(1,N). */

/*  VL      (input) REAL */
/*  VU      (input) REAL */
/*          If RANGE='V', the lower and upper bounds of the interval to */
/*          be searched for eigenvalues. VL < VU. */
/*          Not referenced if RANGE = 'A' or 'I'. */

/*  IL      (input) INTEGER */
/*  IU      (input) INTEGER */
/*          If RANGE='I', the indices (in ascending order) of the */
/*          smallest and largest eigenvalues to be returned. */
/*          1 <= IL <= IU <= N, if N > 0; IL = 1 and IU = 0 if N = 0. */
/*          Not referenced if RANGE = 'A' or 'V'. */

/*  ABSTOL  (input) REAL */
/*          The absolute error tolerance for the eigenvalues. */
/*          An approximate eigenvalue is accepted as converged */
/*          when it is determined to lie in an interval [a,b] */
/*          of width less than or equal to */

/*                  ABSTOL + EPS *   max( |a|,|b| ) , */

/*          where EPS is the machine precision.  If ABSTOL is less than */
/*          or equal to zero, then  EPS*|T|  will be used in its place, */
/*          where |T| is the 1-norm of the tridiagonal matrix obtained */
/*          by reducing AB to tridiagonal form. */

/*          Eigenvalues will be computed most accurately when ABSTOL is */
/*          set to twice the underflow threshold 2*SLAMCH('S'), not zero. */
/*          If this routine returns with INFO>0, indicating that some */
/*          eigenvectors did not converge, try setting ABSTOL to */
/*          2*SLAMCH('S'). */

/*          See "Computing Small Singular Values of Bidiagonal Matrices */
/*          with Guaranteed High Relative Accuracy," by Demmel and */
/*          Kahan, LAPACK Working Note #3. */

/*  M       (output) INTEGER */
/*          The total number of eigenvalues found.  0 <= M <= N. */
/*          If RANGE = 'A', M = N, and if RANGE = 'I', M = IU-IL+1. */

/*  W       (output) REAL array, dimension (N) */
/*          The first M elements contain the selected eigenvalues in */
/*          ascending order. */

/*  Z       (output) COMPLEX array, dimension (LDZ, max(1,M)) */
/*          If JOBZ = 'V', then if INFO = 0, the first M columns of Z */
/*          contain the orthonormal eigenvectors of the matrix A */
/*          corresponding to the selected eigenvalues, with the i-th */
/*          column of Z holding the eigenvector associated with W(i). */
/*          If an eigenvector fails to converge, then that column of Z */
/*          contains the latest approximation to the eigenvector, and the */
/*          index of the eigenvector is returned in IFAIL. */
/*          If JOBZ = 'N', then Z is not referenced. */
/*          Note: the user must ensure that at least max(1,M) columns are */
/*          supplied in the array Z; if RANGE = 'V', the exact value of M */
/*          is not known in advance and an upper bound must be used. */

/*  LDZ     (input) INTEGER */
/*          The leading dimension of the array Z.  LDZ >= 1, and if */
/*          JOBZ = 'V', LDZ >= max(1,N). */

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

/*  RWORK   (workspace) REAL array, dimension (7*N) */

/*  IWORK   (workspace) INTEGER array, dimension (5*N) */

/*  IFAIL   (output) INTEGER array, dimension (N) */
/*          If JOBZ = 'V', then if INFO = 0, the first M elements of */
/*          IFAIL are zero.  If INFO > 0, then IFAIL contains the */
/*          indices of the eigenvectors that failed to converge. */
/*          If JOBZ = 'N', then IFAIL is not referenced. */

/*  INFO    (output) INTEGER */
/*          = 0:  successful exit */
/*          < 0:  if INFO = -i, the i-th argument had an illegal value */
/*          > 0:  if INFO = i, then i eigenvectors failed to converge. */
/*                Their indices are stored in array IFAIL. */

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

/*     Test the input parameters. */

    /* Parameter adjustments */
    ab_dim1 = *ldab;
    ab_offset = 1 + ab_dim1;
    ab -= ab_offset;
    q_dim1 = *ldq;
    q_offset = 1 + q_dim1;
    q -= q_offset;
    --w;
    z_dim1 = *ldz;
    z_offset = 1 + z_dim1;
    z__ -= z_offset;
    --work;
    --rwork;
    --iwork;
    --ifail;

    /* Function Body */
    wantz = lsame_(jobz, "V");
    alleig = lsame_(range, "A");
    valeig = lsame_(range, "V");
    indeig = lsame_(range, "I");
    lower = lsame_(uplo, "L");

    *info = 0;
    if (! (wantz || lsame_(jobz, "N"))) {
	*info = -1;
    } else if (! (alleig || valeig || indeig)) {
	*info = -2;
    } else if (! (lower || lsame_(uplo, "U"))) {
	*info = -3;
    } else if (*n < 0) {
	*info = -4;
    } else if (*kd < 0) {
	*info = -5;
    } else if (*ldab < *kd + 1) {
	*info = -7;
    } else if (wantz && *ldq < max(1,*n)) {
	*info = -9;
    } else {
	if (valeig) {
	    if (*n > 0 && *vu <= *vl) {
		*info = -11;
	    }
	} else if (indeig) {
	    if (*il < 1 || *il > max(1,*n)) {
		*info = -12;
	    } else if (*iu < min(*n,*il) || *iu > *n) {
		*info = -13;
	    }
	}
    }
    if (*info == 0) {
	if (*ldz < 1 || wantz && *ldz < *n) {
	    *info = -18;
	}
    }

    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("CHBEVX", &i__1);
	return 0;
    }

/*     Quick return if possible */

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

    if (*n == 1) {
	*m = 1;
	if (lower) {
	    i__1 = ab_dim1 + 1;
	    ctmp1.r = ab[i__1].r, ctmp1.i = ab[i__1].i;
	} else {
	    i__1 = *kd + 1 + ab_dim1;
	    ctmp1.r = ab[i__1].r, ctmp1.i = ab[i__1].i;
	}
	tmp1 = ctmp1.r;
	if (valeig) {
	    if (! (*vl < tmp1 && *vu >= tmp1)) {
		*m = 0;
	    }
	}
	if (*m == 1) {
	    w[1] = ctmp1.r;
	    if (wantz) {
		i__1 = z_dim1 + 1;
		z__[i__1].r = 1.f, z__[i__1].i = 0.f;
	    }
	}
	return 0;
    }

/*     Get machine constants. */

    safmin = slamch_("Safe minimum");
    eps = slamch_("Precision");
    smlnum = safmin / eps;
    bignum = 1.f / smlnum;
    rmin = sqrt(smlnum);
/* Computing MIN */
    r__1 = sqrt(bignum), r__2 = 1.f / sqrt(sqrt(safmin));
    rmax = dmin(r__1,r__2);

/*     Scale matrix to allowable range, if necessary. */

    iscale = 0;
    abstll = *abstol;
    if (valeig) {
	vll = *vl;
	vuu = *vu;
    } else {
	vll = 0.f;
	vuu = 0.f;
    }
    anrm = clanhb_("M", uplo, n, kd, &ab[ab_offset], ldab, &rwork[1]);
    if (anrm > 0.f && anrm < rmin) {
	iscale = 1;
	sigma = rmin / anrm;
    } else if (anrm > rmax) {
	iscale = 1;
	sigma = rmax / anrm;
    }
    if (iscale == 1) {
	if (lower) {
	    clascl_("B", kd, kd, &c_b16, &sigma, n, n, &ab[ab_offset], ldab, 
		    info);
	} else {
	    clascl_("Q", kd, kd, &c_b16, &sigma, n, n, &ab[ab_offset], ldab, 
		    info);
	}
	if (*abstol > 0.f) {
	    abstll = *abstol * sigma;
	}
	if (valeig) {
	    vll = *vl * sigma;
	    vuu = *vu * sigma;
	}
    }

/*     Call CHBTRD to reduce Hermitian band matrix to tridiagonal form. */

    indd = 1;
    inde = indd + *n;
    indrwk = inde + *n;
    indwrk = 1;
    chbtrd_(jobz, uplo, n, kd, &ab[ab_offset], ldab, &rwork[indd], &rwork[
	    inde], &q[q_offset], ldq, &work[indwrk], &iinfo);

/*     If all eigenvalues are desired and ABSTOL is less than or equal */
/*     to zero, then call SSTERF or CSTEQR.  If this fails for some */
/*     eigenvalue, then try SSTEBZ. */

    test = FALSE_;
    if (indeig) {
	if (*il == 1 && *iu == *n) {
	    test = TRUE_;
	}
    }
    if ((alleig || test) && *abstol <= 0.f) {
	scopy_(n, &rwork[indd], &c__1, &w[1], &c__1);
	indee = indrwk + (*n << 1);
	if (! wantz) {
	    i__1 = *n - 1;
	    scopy_(&i__1, &rwork[inde], &c__1, &rwork[indee], &c__1);
	    ssterf_(n, &w[1], &rwork[indee], info);
	} else {
	    clacpy_("A", n, n, &q[q_offset], ldq, &z__[z_offset], ldz);
	    i__1 = *n - 1;
	    scopy_(&i__1, &rwork[inde], &c__1, &rwork[indee], &c__1);
	    csteqr_(jobz, n, &w[1], &rwork[indee], &z__[z_offset], ldz, &
		    rwork[indrwk], info);
	    if (*info == 0) {
		i__1 = *n;
		for (i__ = 1; i__ <= i__1; ++i__) {
		    ifail[i__] = 0;
		}
	    }
	}
	if (*info == 0) {
	    *m = *n;
	    goto L30;
	}
	*info = 0;
    }

/*     Otherwise, call SSTEBZ and, if eigenvectors are desired, CSTEIN. */

    if (wantz) {
	*(unsigned char *)order = 'B';
    } else {
	*(unsigned char *)order = 'E';
    }
    indibl = 1;
    indisp = indibl + *n;
    indiwk = indisp + *n;
    sstebz_(range, order, n, &vll, &vuu, il, iu, &abstll, &rwork[indd], &
	    rwork[inde], m, &nsplit, &w[1], &iwork[indibl], &iwork[indisp], &
	    rwork[indrwk], &iwork[indiwk], info);

    if (wantz) {
	cstein_(n, &rwork[indd], &rwork[inde], m, &w[1], &iwork[indibl], &
		iwork[indisp], &z__[z_offset], ldz, &rwork[indrwk], &iwork[
		indiwk], &ifail[1], info);

/*        Apply unitary matrix used in reduction to tridiagonal */
/*        form to eigenvectors returned by CSTEIN. */

	i__1 = *m;
	for (j = 1; j <= i__1; ++j) {
	    ccopy_(n, &z__[j * z_dim1 + 1], &c__1, &work[1], &c__1);
	    cgemv_("N", n, n, &c_b2, &q[q_offset], ldq, &work[1], &c__1, &
		    c_b1, &z__[j * z_dim1 + 1], &c__1);
	}
    }

/*     If matrix was scaled, then rescale eigenvalues appropriately. */

L30:
    if (iscale == 1) {
	if (*info == 0) {
	    imax = *m;
	} else {
	    imax = *info - 1;
	}
	r__1 = 1.f / sigma;
	sscal_(&imax, &r__1, &w[1], &c__1);
    }

/*     If eigenvalues are not in order, then sort them, along with */
/*     eigenvectors. */

    if (wantz) {
	i__1 = *m - 1;
	for (j = 1; j <= i__1; ++j) {
	    i__ = 0;
	    tmp1 = w[j];
	    i__2 = *m;
	    for (jj = j + 1; jj <= i__2; ++jj) {
		if (w[jj] < tmp1) {
		    i__ = jj;
		    tmp1 = w[jj];
		}
	    }

	    if (i__ != 0) {
		itmp1 = iwork[indibl + i__ - 1];
		w[i__] = w[j];
		iwork[indibl + i__ - 1] = iwork[indibl + j - 1];
		w[j] = tmp1;
		iwork[indibl + j - 1] = itmp1;
		cswap_(n, &z__[i__ * z_dim1 + 1], &c__1, &z__[j * z_dim1 + 1], 
			 &c__1);
		if (*info != 0) {
		    itmp1 = ifail[i__];
		    ifail[i__] = ifail[j];
		    ifail[j] = itmp1;
		}
	    }
	}
    }

    return 0;

/*     End of CHBEVX */

} /* chbevx_ */
Exemplo n.º 6
0
/* Subroutine */ int cchkpb_(logical *dotype, integer *nn, integer *nval, 
	integer *nnb, integer *nbval, integer *nns, integer *nsval, real *
	thresh, logical *tsterr, integer *nmax, complex *a, complex *afac, 
	complex *ainv, complex *b, complex *x, complex *xact, complex *work, 
	real *rwork, integer *nout)
{
    /* Initialized data */

    static integer iseedy[4] = { 1988,1989,1990,1991 };

    /* Format strings */
    static char fmt_9999[] = "(\002 UPLO='\002,a1,\002', N=\002,i5,\002, KD"
	    "=\002,i5,\002, NB=\002,i4,\002, type \002,i2,\002, test \002,i2"
	    ",\002, ratio= \002,g12.5)";
    static char fmt_9998[] = "(\002 UPLO='\002,a1,\002', N=\002,i5,\002, KD"
	    "=\002,i5,\002, NRHS=\002,i3,\002, type \002,i2,\002, test(\002,i"
	    "2,\002) = \002,g12.5)";
    static char fmt_9997[] = "(\002 UPLO='\002,a1,\002', N=\002,i5,\002, KD"
	    "=\002,i5,\002,\002,10x,\002 type \002,i2,\002, test(\002,i2,\002"
	    ") = \002,g12.5)";

    /* System generated locals */
    integer i__1, i__2, i__3, i__4, i__5, i__6;

    /* Local variables */
    integer i__, k, n, i1, i2, kd, nb, in, kl, iw, ku, lda, ikd, inb, nkd, 
	    ldab, ioff, mode, koff, imat, info;
    char path[3], dist[1];
    integer irhs, nrhs;
    char uplo[1], type__[1];
    integer nrun;
    integer nfail, iseed[4];
    integer kdval[4];
    real rcond;
    integer nimat;
    real anorm;
    integer iuplo, izero, nerrs;
    logical zerot;
    char xtype[1];
    real rcondc;
    char packit[1];
    real cndnum;
    real ainvnm;
    real result[7];

    /* Fortran I/O blocks */
    static cilist io___40 = { 0, 0, 0, fmt_9999, 0 };
    static cilist io___46 = { 0, 0, 0, fmt_9998, 0 };
    static cilist io___48 = { 0, 0, 0, fmt_9997, 0 };



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

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

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

/*  CCHKPB tests CPBTRF, -TRS, -RFS, and -CON. */

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

/*  DOTYPE  (input) LOGICAL array, dimension (NTYPES) */
/*          The matrix types to be used for testing.  Matrices of type j */
/*          (for 1 <= j <= NTYPES) are used for testing if DOTYPE(j) = */
/*          .TRUE.; if DOTYPE(j) = .FALSE., then type j is not used. */

/*  NN      (input) INTEGER */
/*          The number of values of N contained in the vector NVAL. */

/*  NVAL    (input) INTEGER array, dimension (NN) */
/*          The values of the matrix dimension N. */

/*  NNB     (input) INTEGER */
/*          The number of values of NB contained in the vector NBVAL. */

/*  NBVAL   (input) INTEGER array, dimension (NBVAL) */
/*          The values of the blocksize NB. */

/*  NNS     (input) INTEGER */
/*          The number of values of NRHS contained in the vector NSVAL. */

/*  NSVAL   (input) INTEGER array, dimension (NNS) */
/*          The values of the number of right hand sides NRHS. */

/*  THRESH  (input) REAL */
/*          The threshold value for the test ratios.  A result is */
/*          included in the output file if RESULT >= THRESH.  To have */
/*          every test ratio printed, use THRESH = 0. */

/*  TSTERR  (input) LOGICAL */
/*          Flag that indicates whether error exits are to be tested. */

/*  NMAX    (input) INTEGER */
/*          The maximum value permitted for N, used in dimensioning the */
/*          work arrays. */

/*  A       (workspace) REAL array, dimension (NMAX*NMAX) */

/*  AFAC    (workspace) REAL array, dimension (NMAX*NMAX) */

/*  AINV    (workspace) REAL array, dimension (NMAX*NMAX) */

/*  B       (workspace) REAL array, dimension (NMAX*NSMAX) */
/*          where NSMAX is the largest entry in NSVAL. */

/*  X       (workspace) REAL array, dimension (NMAX*NSMAX) */

/*  XACT    (workspace) REAL array, dimension (NMAX*NSMAX) */

/*  WORK    (workspace) REAL array, dimension */
/*                      (NMAX*max(3,NSMAX)) */

/*  RWORK   (workspace) REAL array, dimension */
/*                      (max(NMAX,2*NSMAX)) */

/*  NOUT    (input) INTEGER */
/*          The unit number for output. */

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

/*     .. Parameters .. */
/*     .. */
/*     .. Local Scalars .. */
/*     .. */
/*     .. Local Arrays .. */
/*     .. */
/*     .. External Functions .. */
/*     .. */
/*     .. External Subroutines .. */
/*     .. */
/*     .. Intrinsic Functions .. */
/*     .. */
/*     .. Scalars in Common .. */
/*     .. */
/*     .. Common blocks .. */
/*     .. */
/*     .. Data statements .. */
    /* Parameter adjustments */
    --rwork;
    --work;
    --xact;
    --x;
    --b;
    --ainv;
    --afac;
    --a;
    --nsval;
    --nbval;
    --nval;
    --dotype;

    /* Function Body */
/*     .. */
/*     .. Executable Statements .. */

/*     Initialize constants and the random number seed. */

    s_copy(path, "Complex precision", (ftnlen)1, (ftnlen)17);
    s_copy(path + 1, "PB", (ftnlen)2, (ftnlen)2);
    nrun = 0;
    nfail = 0;
    nerrs = 0;
    for (i__ = 1; i__ <= 4; ++i__) {
	iseed[i__ - 1] = iseedy[i__ - 1];
/* L10: */
    }

/*     Test the error exits */

    if (*tsterr) {
	cerrpo_(path, nout);
    }
    infoc_1.infot = 0;
    kdval[0] = 0;

/*     Do for each value of N in NVAL */

    i__1 = *nn;
    for (in = 1; in <= i__1; ++in) {
	n = nval[in];
	lda = max(n,1);
	*(unsigned char *)xtype = 'N';

/*        Set limits on the number of loop iterations. */

/* Computing MAX */
	i__2 = 1, i__3 = min(n,4);
	nkd = max(i__2,i__3);
	nimat = 8;
	if (n == 0) {
	    nimat = 1;
	}

	kdval[1] = n + (n + 1) / 4;
	kdval[2] = (n * 3 - 1) / 4;
	kdval[3] = (n + 1) / 4;

	i__2 = nkd;
	for (ikd = 1; ikd <= i__2; ++ikd) {

/*           Do for KD = 0, (5*N+1)/4, (3N-1)/4, and (N+1)/4. This order */
/*           makes it easier to skip redundant values for small values */
/*           of N. */

	    kd = kdval[ikd - 1];
	    ldab = kd + 1;

/*           Do first for UPLO = 'U', then for UPLO = 'L' */

	    for (iuplo = 1; iuplo <= 2; ++iuplo) {
		koff = 1;
		if (iuplo == 1) {
		    *(unsigned char *)uplo = 'U';
/* Computing MAX */
		    i__3 = 1, i__4 = kd + 2 - n;
		    koff = max(i__3,i__4);
		    *(unsigned char *)packit = 'Q';
		} else {
		    *(unsigned char *)uplo = 'L';
		    *(unsigned char *)packit = 'B';
		}

		i__3 = nimat;
		for (imat = 1; imat <= i__3; ++imat) {

/*                 Do the tests only if DOTYPE( IMAT ) is true. */

		    if (! dotype[imat]) {
			goto L60;
		    }

/*                 Skip types 2, 3, or 4 if the matrix size is too small. */

		    zerot = imat >= 2 && imat <= 4;
		    if (zerot && n < imat - 1) {
			goto L60;
		    }

		    if (! zerot || ! dotype[1]) {

/*                    Set up parameters with CLATB4 and generate a test */
/*                    matrix with CLATMS. */

			clatb4_(path, &imat, &n, &n, type__, &kl, &ku, &anorm, 
				 &mode, &cndnum, dist);

			s_copy(srnamc_1.srnamt, "CLATMS", (ftnlen)32, (ftnlen)
				6);
			clatms_(&n, &n, dist, iseed, type__, &rwork[1], &mode, 
				 &cndnum, &anorm, &kd, &kd, packit, &a[koff], 
				&ldab, &work[1], &info);

/*                    Check error code from CLATMS. */

			if (info != 0) {
			    alaerh_(path, "CLATMS", &info, &c__0, uplo, &n, &
				    n, &kd, &kd, &c_n1, &imat, &nfail, &nerrs, 
				     nout);
			    goto L60;
			}
		    } else if (izero > 0) {

/*                    Use the same matrix for types 3 and 4 as for type */
/*                    2 by copying back the zeroed out column, */

			iw = (lda << 1) + 1;
			if (iuplo == 1) {
			    ioff = (izero - 1) * ldab + kd + 1;
			    i__4 = izero - i1;
			    ccopy_(&i__4, &work[iw], &c__1, &a[ioff - izero + 
				    i1], &c__1);
			    iw = iw + izero - i1;
			    i__4 = i2 - izero + 1;
/* Computing MAX */
			    i__6 = ldab - 1;
			    i__5 = max(i__6,1);
			    ccopy_(&i__4, &work[iw], &c__1, &a[ioff], &i__5);
			} else {
			    ioff = (i1 - 1) * ldab + 1;
			    i__4 = izero - i1;
/* Computing MAX */
			    i__6 = ldab - 1;
			    i__5 = max(i__6,1);
			    ccopy_(&i__4, &work[iw], &c__1, &a[ioff + izero - 
				    i1], &i__5);
			    ioff = (izero - 1) * ldab + 1;
			    iw = iw + izero - i1;
			    i__4 = i2 - izero + 1;
			    ccopy_(&i__4, &work[iw], &c__1, &a[ioff], &c__1);
			}
		    }

/*                 For types 2-4, zero one row and column of the matrix */
/*                 to test that INFO is returned correctly. */

		    izero = 0;
		    if (zerot) {
			if (imat == 2) {
			    izero = 1;
			} else if (imat == 3) {
			    izero = n;
			} else {
			    izero = n / 2 + 1;
			}

/*                    Save the zeroed out row and column in WORK(*,3) */

			iw = lda << 1;
/* Computing MIN */
			i__5 = (kd << 1) + 1;
			i__4 = min(i__5,n);
			for (i__ = 1; i__ <= i__4; ++i__) {
			    i__5 = iw + i__;
			    work[i__5].r = 0.f, work[i__5].i = 0.f;
/* L20: */
			}
			++iw;
/* Computing MAX */
			i__4 = izero - kd;
			i1 = max(i__4,1);
/* Computing MIN */
			i__4 = izero + kd;
			i2 = min(i__4,n);

			if (iuplo == 1) {
			    ioff = (izero - 1) * ldab + kd + 1;
			    i__4 = izero - i1;
			    cswap_(&i__4, &a[ioff - izero + i1], &c__1, &work[
				    iw], &c__1);
			    iw = iw + izero - i1;
			    i__4 = i2 - izero + 1;
/* Computing MAX */
			    i__6 = ldab - 1;
			    i__5 = max(i__6,1);
			    cswap_(&i__4, &a[ioff], &i__5, &work[iw], &c__1);
			} else {
			    ioff = (i1 - 1) * ldab + 1;
			    i__4 = izero - i1;
/* Computing MAX */
			    i__6 = ldab - 1;
			    i__5 = max(i__6,1);
			    cswap_(&i__4, &a[ioff + izero - i1], &i__5, &work[
				    iw], &c__1);
			    ioff = (izero - 1) * ldab + 1;
			    iw = iw + izero - i1;
			    i__4 = i2 - izero + 1;
			    cswap_(&i__4, &a[ioff], &c__1, &work[iw], &c__1);
			}
		    }

/*                 Set the imaginary part of the diagonals. */

		    if (iuplo == 1) {
			claipd_(&n, &a[kd + 1], &ldab, &c__0);
		    } else {
			claipd_(&n, &a[1], &ldab, &c__0);
		    }

/*                 Do for each value of NB in NBVAL */

		    i__4 = *nnb;
		    for (inb = 1; inb <= i__4; ++inb) {
			nb = nbval[inb];
			xlaenv_(&c__1, &nb);

/*                    Compute the L*L' or U'*U factorization of the band */
/*                    matrix. */

			i__5 = kd + 1;
			clacpy_("Full", &i__5, &n, &a[1], &ldab, &afac[1], &
				ldab);
			s_copy(srnamc_1.srnamt, "CPBTRF", (ftnlen)32, (ftnlen)
				6);
			cpbtrf_(uplo, &n, &kd, &afac[1], &ldab, &info);

/*                    Check error code from CPBTRF. */

			if (info != izero) {
			    alaerh_(path, "CPBTRF", &info, &izero, uplo, &n, &
				    n, &kd, &kd, &nb, &imat, &nfail, &nerrs, 
				    nout);
			    goto L50;
			}

/*                    Skip the tests if INFO is not 0. */

			if (info != 0) {
			    goto L50;
			}

/* +    TEST 1 */
/*                    Reconstruct matrix from factors and compute */
/*                    residual. */

			i__5 = kd + 1;
			clacpy_("Full", &i__5, &n, &afac[1], &ldab, &ainv[1], 
				&ldab);
			cpbt01_(uplo, &n, &kd, &a[1], &ldab, &ainv[1], &ldab, 
				&rwork[1], result);

/*                    Print the test ratio if it is .GE. THRESH. */

			if (result[0] >= *thresh) {
			    if (nfail == 0 && nerrs == 0) {
				alahd_(nout, path);
			    }
			    io___40.ciunit = *nout;
			    s_wsfe(&io___40);
			    do_fio(&c__1, uplo, (ftnlen)1);
			    do_fio(&c__1, (char *)&n, (ftnlen)sizeof(integer))
				    ;
			    do_fio(&c__1, (char *)&kd, (ftnlen)sizeof(integer)
				    );
			    do_fio(&c__1, (char *)&nb, (ftnlen)sizeof(integer)
				    );
			    do_fio(&c__1, (char *)&imat, (ftnlen)sizeof(
				    integer));
			    do_fio(&c__1, (char *)&c__1, (ftnlen)sizeof(
				    integer));
			    do_fio(&c__1, (char *)&result[0], (ftnlen)sizeof(
				    real));
			    e_wsfe();
			    ++nfail;
			}
			++nrun;

/*                    Only do other tests if this is the first blocksize. */

			if (inb > 1) {
			    goto L50;
			}

/*                    Form the inverse of A so we can get a good estimate */
/*                    of RCONDC = 1/(norm(A) * norm(inv(A))). */

			claset_("Full", &n, &n, &c_b50, &c_b51, &ainv[1], &
				lda);
			s_copy(srnamc_1.srnamt, "CPBTRS", (ftnlen)32, (ftnlen)
				6);
			cpbtrs_(uplo, &n, &kd, &n, &afac[1], &ldab, &ainv[1], 
				&lda, &info);

/*                    Compute RCONDC = 1/(norm(A) * norm(inv(A))). */

			anorm = clanhb_("1", uplo, &n, &kd, &a[1], &ldab, &
				rwork[1]);
			ainvnm = clange_("1", &n, &n, &ainv[1], &lda, &rwork[
				1]);
			if (anorm <= 0.f || ainvnm <= 0.f) {
			    rcondc = 1.f;
			} else {
			    rcondc = 1.f / anorm / ainvnm;
			}

			i__5 = *nns;
			for (irhs = 1; irhs <= i__5; ++irhs) {
			    nrhs = nsval[irhs];

/* +    TEST 2 */
/*                    Solve and compute residual for A * X = B. */

			    s_copy(srnamc_1.srnamt, "CLARHS", (ftnlen)32, (
				    ftnlen)6);
			    clarhs_(path, xtype, uplo, " ", &n, &n, &kd, &kd, 
				    &nrhs, &a[1], &ldab, &xact[1], &lda, &b[1]
, &lda, iseed, &info);
			    clacpy_("Full", &n, &nrhs, &b[1], &lda, &x[1], &
				    lda);

			    s_copy(srnamc_1.srnamt, "CPBTRS", (ftnlen)32, (
				    ftnlen)6);
			    cpbtrs_(uplo, &n, &kd, &nrhs, &afac[1], &ldab, &x[
				    1], &lda, &info);

/*                    Check error code from CPBTRS. */

			    if (info != 0) {
				alaerh_(path, "CPBTRS", &info, &c__0, uplo, &
					n, &n, &kd, &kd, &nrhs, &imat, &nfail, 
					 &nerrs, nout);
			    }

			    clacpy_("Full", &n, &nrhs, &b[1], &lda, &work[1], 
				    &lda);
			    cpbt02_(uplo, &n, &kd, &nrhs, &a[1], &ldab, &x[1], 
				     &lda, &work[1], &lda, &rwork[1], &result[
				    1]);

/* +    TEST 3 */
/*                    Check solution from generated exact solution. */

			    cget04_(&n, &nrhs, &x[1], &lda, &xact[1], &lda, &
				    rcondc, &result[2]);

/* +    TESTS 4, 5, and 6 */
/*                    Use iterative refinement to improve the solution. */

			    s_copy(srnamc_1.srnamt, "CPBRFS", (ftnlen)32, (
				    ftnlen)6);
			    cpbrfs_(uplo, &n, &kd, &nrhs, &a[1], &ldab, &afac[
				    1], &ldab, &b[1], &lda, &x[1], &lda, &
				    rwork[1], &rwork[nrhs + 1], &work[1], &
				    rwork[(nrhs << 1) + 1], &info);

/*                    Check error code from CPBRFS. */

			    if (info != 0) {
				alaerh_(path, "CPBRFS", &info, &c__0, uplo, &
					n, &n, &kd, &kd, &nrhs, &imat, &nfail, 
					 &nerrs, nout);
			    }

			    cget04_(&n, &nrhs, &x[1], &lda, &xact[1], &lda, &
				    rcondc, &result[3]);
			    cpbt05_(uplo, &n, &kd, &nrhs, &a[1], &ldab, &b[1], 
				     &lda, &x[1], &lda, &xact[1], &lda, &
				    rwork[1], &rwork[nrhs + 1], &result[4]);

/*                       Print information about the tests that did not */
/*                       pass the threshold. */

			    for (k = 2; k <= 6; ++k) {
				if (result[k - 1] >= *thresh) {
				    if (nfail == 0 && nerrs == 0) {
					alahd_(nout, path);
				    }
				    io___46.ciunit = *nout;
				    s_wsfe(&io___46);
				    do_fio(&c__1, uplo, (ftnlen)1);
				    do_fio(&c__1, (char *)&n, (ftnlen)sizeof(
					    integer));
				    do_fio(&c__1, (char *)&kd, (ftnlen)sizeof(
					    integer));
				    do_fio(&c__1, (char *)&nrhs, (ftnlen)
					    sizeof(integer));
				    do_fio(&c__1, (char *)&imat, (ftnlen)
					    sizeof(integer));
				    do_fio(&c__1, (char *)&k, (ftnlen)sizeof(
					    integer));
				    do_fio(&c__1, (char *)&result[k - 1], (
					    ftnlen)sizeof(real));
				    e_wsfe();
				    ++nfail;
				}
/* L30: */
			    }
			    nrun += 5;
/* L40: */
			}

/* +    TEST 7 */
/*                    Get an estimate of RCOND = 1/CNDNUM. */

			s_copy(srnamc_1.srnamt, "CPBCON", (ftnlen)32, (ftnlen)
				6);
			cpbcon_(uplo, &n, &kd, &afac[1], &ldab, &anorm, &
				rcond, &work[1], &rwork[1], &info);

/*                    Check error code from CPBCON. */

			if (info != 0) {
			    alaerh_(path, "CPBCON", &info, &c__0, uplo, &n, &
				    n, &kd, &kd, &c_n1, &imat, &nfail, &nerrs, 
				     nout);
			}

			result[6] = sget06_(&rcond, &rcondc);

/*                    Print the test ratio if it is .GE. THRESH. */

			if (result[6] >= *thresh) {
			    if (nfail == 0 && nerrs == 0) {
				alahd_(nout, path);
			    }
			    io___48.ciunit = *nout;
			    s_wsfe(&io___48);
			    do_fio(&c__1, uplo, (ftnlen)1);
			    do_fio(&c__1, (char *)&n, (ftnlen)sizeof(integer))
				    ;
			    do_fio(&c__1, (char *)&kd, (ftnlen)sizeof(integer)
				    );
			    do_fio(&c__1, (char *)&imat, (ftnlen)sizeof(
				    integer));
			    do_fio(&c__1, (char *)&c__7, (ftnlen)sizeof(
				    integer));
			    do_fio(&c__1, (char *)&result[6], (ftnlen)sizeof(
				    real));
			    e_wsfe();
			    ++nfail;
			}
			++nrun;
L50:
			;
		    }
L60:
		    ;
		}
/* L70: */
	    }
/* L80: */
	}
/* L90: */
    }

/*     Print a summary of the results. */

    alasum_(path, nout, &nfail, &nrun, &nerrs);

    return 0;

/*     End of CCHKPB */

} /* cchkpb_ */
Exemplo n.º 7
0
 int cpbsvx_(char *fact, char *uplo, int *n, int *kd, 
	int *nrhs, complex *ab, int *ldab, complex *afb, int *
	ldafb, char *equed, float *s, complex *b, int *ldb, complex *x, 
	int *ldx, float *rcond, float *ferr, float *berr, complex *work, 
	float *rwork, int *info)
{
    /* System generated locals */
    int ab_dim1, ab_offset, afb_dim1, afb_offset, b_dim1, b_offset, 
	    x_dim1, x_offset, i__1, i__2, i__3, i__4, i__5;
    float r__1, r__2;
    complex q__1;

    /* Local variables */
    int i__, j, j1, j2;
    float amax, smin, smax;
    extern int lsame_(char *, char *);
    float scond, anorm;
    extern  int ccopy_(int *, complex *, int *, 
	    complex *, int *);
    int equil, rcequ, upper;
    extern double clanhb_(char *, char *, int *, int *, complex *, 
	     int *, float *);
    extern  int claqhb_(char *, int *, int *, complex 
	    *, int *, float *, float *, float *, char *), 
	    cpbcon_(char *, int *, int *, complex *, int *, float *
, float *, complex *, float *, int *);
    extern double slamch_(char *);
    int nofact;
    extern  int clacpy_(char *, int *, int *, complex 
	    *, int *, complex *, int *), xerbla_(char *, 
	    int *), cpbequ_(char *, int *, int *, complex 
	    *, int *, float *, float *, float *, int *), cpbrfs_(
	    char *, int *, int *, int *, complex *, int *, 
	    complex *, int *, complex *, int *, complex *, int *, 
	    float *, float *, complex *, float *, int *);
    float bignum;
    extern  int cpbtrf_(char *, int *, int *, complex 
	    *, int *, int *);
    int infequ;
    extern  int cpbtrs_(char *, int *, int *, int 
	    *, complex *, int *, complex *, int *, int *);
    float smlnum;


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

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

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

/*  CPBSVX uses the Cholesky factorization A = U**H*U or A = L*L**H to */
/*  compute the solution to a complex system of linear equations */
/*     A * X = B, */
/*  where A is an N-by-N Hermitian positive definite band matrix and X */
/*  and B are N-by-NRHS matrices. */

/*  Error bounds on the solution and a condition estimate are also */
/*  provided. */

/*  Description */
/*  =========== */

/*  The following steps are performed: */

/*  1. If FACT = 'E', float scaling factors are computed to equilibrate */
/*     the system: */
/*        diag(S) * A * diag(S) * inv(diag(S)) * X = diag(S) * B */
/*     Whether or not the system will be equilibrated depends on the */
/*     scaling of the matrix A, but if equilibration is used, A is */
/*     overwritten by diag(S)*A*diag(S) and B by diag(S)*B. */

/*  2. If FACT = 'N' or 'E', the Cholesky decomposition is used to */
/*     factor the matrix A (after equilibration if FACT = 'E') as */
/*        A = U**H * U,  if UPLO = 'U', or */
/*        A = L * L**H,  if UPLO = 'L', */
/*     where U is an upper triangular band matrix, and L is a lower */
/*     triangular band matrix. */

/*  3. If the leading i-by-i principal minor is not positive definite, */
/*     then the routine returns with INFO = i. Otherwise, the factored */
/*     form of A is used to estimate the condition number of the matrix */
/*     A.  If the reciprocal of the condition number is less than machine */
/*     precision, INFO = N+1 is returned as a warning, but the routine */
/*     still goes on to solve for X and compute error bounds as */
/*     described below. */

/*  4. The system of equations is solved for X using the factored form */
/*     of A. */

/*  5. Iterative refinement is applied to improve the computed solution */
/*     matrix and calculate error bounds and backward error estimates */
/*     for it. */

/*  6. If equilibration was used, the matrix X is premultiplied by */
/*     diag(S) so that it solves the original system before */
/*     equilibration. */

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

/*  FACT    (input) CHARACTER*1 */
/*          Specifies whether or not the factored form of the matrix A is */
/*          supplied on entry, and if not, whether the matrix A should be */
/*          equilibrated before it is factored. */
/*          = 'F':  On entry, AFB contains the factored form of A. */
/*                  If EQUED = 'Y', the matrix A has been equilibrated */
/*                  with scaling factors given by S.  AB and AFB will not */
/*                  be modified. */
/*          = 'N':  The matrix A will be copied to AFB and factored. */
/*          = 'E':  The matrix A will be equilibrated if necessary, then */
/*                  copied to AFB and factored. */

/*  UPLO    (input) CHARACTER*1 */
/*          = 'U':  Upper triangle of A is stored; */
/*          = 'L':  Lower triangle of A is stored. */

/*  N       (input) INTEGER */
/*          The number of linear equations, i.e., the order of the */
/*          matrix A.  N >= 0. */

/*  KD      (input) INTEGER */
/*          The number of superdiagonals of the matrix A if UPLO = 'U', */
/*          or the number of subdiagonals if UPLO = 'L'.  KD >= 0. */

/*  NRHS    (input) INTEGER */
/*          The number of right-hand sides, i.e., the number of columns */
/*          of the matrices B and X.  NRHS >= 0. */

/*  AB      (input/output) COMPLEX array, dimension (LDAB,N) */
/*          On entry, the upper or lower triangle of the Hermitian band */
/*          matrix A, stored in the first KD+1 rows of the array, except */
/*          if FACT = 'F' and EQUED = 'Y', then A must contain the */
/*          equilibrated matrix diag(S)*A*diag(S).  The j-th column of A */
/*          is stored in the j-th column of the array AB as follows: */
/*          if UPLO = 'U', AB(KD+1+i-j,j) = A(i,j) for MAX(1,j-KD)<=i<=j; */
/*          if UPLO = 'L', AB(1+i-j,j)    = A(i,j) for j<=i<=MIN(N,j+KD). */
/*          See below for further details. */

/*          On exit, if FACT = 'E' and EQUED = 'Y', A is overwritten by */
/*          diag(S)*A*diag(S). */

/*  LDAB    (input) INTEGER */
/*          The leading dimension of the array A.  LDAB >= KD+1. */

/*  AFB     (input or output) COMPLEX array, dimension (LDAFB,N) */
/*          If FACT = 'F', then AFB is an input argument and on entry */
/*          contains the triangular factor U or L from the Cholesky */
/*          factorization A = U**H*U or A = L*L**H of the band matrix */
/*          A, in the same storage format as A (see AB).  If EQUED = 'Y', */
/*          then AFB is the factored form of the equilibrated matrix A. */

/*          If FACT = 'N', then AFB is an output argument and on exit */
/*          returns the triangular factor U or L from the Cholesky */
/*          factorization A = U**H*U or A = L*L**H. */

/*          If FACT = 'E', then AFB is an output argument and on exit */
/*          returns the triangular factor U or L from the Cholesky */
/*          factorization A = U**H*U or A = L*L**H of the equilibrated */
/*          matrix A (see the description of A for the form of the */
/*          equilibrated matrix). */

/*  LDAFB   (input) INTEGER */
/*          The leading dimension of the array AFB.  LDAFB >= KD+1. */

/*  EQUED   (input or output) CHARACTER*1 */
/*          Specifies the form of equilibration that was done. */
/*          = 'N':  No equilibration (always true if FACT = 'N'). */
/*          = 'Y':  Equilibration was done, i.e., A has been replaced by */
/*                  diag(S) * A * diag(S). */
/*          EQUED is an input argument if FACT = 'F'; otherwise, it is an */
/*          output argument. */

/*  S       (input or output) REAL array, dimension (N) */
/*          The scale factors for A; not accessed if EQUED = 'N'.  S is */
/*          an input argument if FACT = 'F'; otherwise, S is an output */
/*          argument.  If FACT = 'F' and EQUED = 'Y', each element of S */
/*          must be positive. */

/*  B       (input/output) COMPLEX array, dimension (LDB,NRHS) */
/*          On entry, the N-by-NRHS right hand side matrix B. */
/*          On exit, if EQUED = 'N', B is not modified; if EQUED = 'Y', */
/*          B is overwritten by diag(S) * B. */

/*  LDB     (input) INTEGER */
/*          The leading dimension of the array B.  LDB >= MAX(1,N). */

/*  X       (output) COMPLEX array, dimension (LDX,NRHS) */
/*          If INFO = 0 or INFO = N+1, the N-by-NRHS solution matrix X to */
/*          the original system of equations.  Note that if EQUED = 'Y', */
/*          A and B are modified on exit, and the solution to the */
/*          equilibrated system is inv(diag(S))*X. */

/*  LDX     (input) INTEGER */
/*          The leading dimension of the array X.  LDX >= MAX(1,N). */

/*  RCOND   (output) REAL */
/*          The estimate of the reciprocal condition number of the matrix */
/*          A after equilibration (if done).  If RCOND is less than the */
/*          machine precision (in particular, if RCOND = 0), the matrix */
/*          is singular to working precision.  This condition is */
/*          indicated by a return code of INFO > 0. */

/*  FERR    (output) REAL array, dimension (NRHS) */
/*          The estimated forward error bound for each solution vector */
/*          X(j) (the j-th column of the solution matrix X). */
/*          If XTRUE is the true solution corresponding to X(j), FERR(j) */
/*          is an estimated upper bound for the magnitude of the largest */
/*          element in (X(j) - XTRUE) divided by the magnitude of the */
/*          largest element in X(j).  The estimate is as reliable as */
/*          the estimate for RCOND, and is almost always a slight */
/*          overestimate of the true error. */

/*  BERR    (output) REAL array, dimension (NRHS) */
/*          The componentwise relative backward error of each solution */
/*          vector X(j) (i.e., the smallest relative change in */
/*          any element of A or B that makes X(j) an exact solution). */

/*  WORK    (workspace) COMPLEX array, dimension (2*N) */

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

/*  INFO    (output) INTEGER */
/*          = 0: successful exit */
/*          < 0: if INFO = -i, the i-th argument had an illegal value */
/*          > 0: if INFO = i, and i is */
/*                <= N:  the leading minor of order i of A is */
/*                       not positive definite, so the factorization */
/*                       could not be completed, and the solution has not */
/*                       been computed. RCOND = 0 is returned. */
/*                = N+1: U is nonsingular, but RCOND is less than machine */
/*                       precision, meaning that the matrix is singular */
/*                       to working precision.  Nevertheless, the */
/*                       solution and error bounds are computed because */
/*                       there are a number of situations where the */
/*                       computed solution can be more accurate than the */
/*                       value of RCOND would suggest. */

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

/*  The band storage scheme is illustrated by the following example, when */
/*  N = 6, KD = 2, and UPLO = 'U': */

/*  Two-dimensional storage of the Hermitian matrix A: */

/*     a11  a12  a13 */
/*          a22  a23  a24 */
/*               a33  a34  a35 */
/*                    a44  a45  a46 */
/*                         a55  a56 */
/*     (aij=conjg(aji))         a66 */

/*  Band storage of the upper triangle of A: */

/*      *    *   a13  a24  a35  a46 */
/*      *   a12  a23  a34  a45  a56 */
/*     a11  a22  a33  a44  a55  a66 */

/*  Similarly, if UPLO = 'L' the format of A is as follows: */

/*     a11  a22  a33  a44  a55  a66 */
/*     a21  a32  a43  a54  a65   * */
/*     a31  a42  a53  a64   *    * */

/*  Array elements marked * are not used by the routine. */

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

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

    /* Parameter adjustments */
    ab_dim1 = *ldab;
    ab_offset = 1 + ab_dim1;
    ab -= ab_offset;
    afb_dim1 = *ldafb;
    afb_offset = 1 + afb_dim1;
    afb -= afb_offset;
    --s;
    b_dim1 = *ldb;
    b_offset = 1 + b_dim1;
    b -= b_offset;
    x_dim1 = *ldx;
    x_offset = 1 + x_dim1;
    x -= x_offset;
    --ferr;
    --berr;
    --work;
    --rwork;

    /* Function Body */
    *info = 0;
    nofact = lsame_(fact, "N");
    equil = lsame_(fact, "E");
    upper = lsame_(uplo, "U");
    if (nofact || equil) {
	*(unsigned char *)equed = 'N';
	rcequ = FALSE;
    } else {
	rcequ = lsame_(equed, "Y");
	smlnum = slamch_("Safe minimum");
	bignum = 1.f / smlnum;
    }

/*     Test the input parameters. */

    if (! nofact && ! equil && ! lsame_(fact, "F")) {
	*info = -1;
    } else if (! upper && ! lsame_(uplo, "L")) {
	*info = -2;
    } else if (*n < 0) {
	*info = -3;
    } else if (*kd < 0) {
	*info = -4;
    } else if (*nrhs < 0) {
	*info = -5;
    } else if (*ldab < *kd + 1) {
	*info = -7;
    } else if (*ldafb < *kd + 1) {
	*info = -9;
    } else if (lsame_(fact, "F") && ! (rcequ || lsame_(
	    equed, "N"))) {
	*info = -10;
    } else {
	if (rcequ) {
	    smin = bignum;
	    smax = 0.f;
	    i__1 = *n;
	    for (j = 1; j <= i__1; ++j) {
/* Computing MIN */
		r__1 = smin, r__2 = s[j];
		smin = MIN(r__1,r__2);
/* Computing MAX */
		r__1 = smax, r__2 = s[j];
		smax = MAX(r__1,r__2);
/* L10: */
	    }
	    if (smin <= 0.f) {
		*info = -11;
	    } else if (*n > 0) {
		scond = MAX(smin,smlnum) / MIN(smax,bignum);
	    } else {
		scond = 1.f;
	    }
	}
	if (*info == 0) {
	    if (*ldb < MAX(1,*n)) {
		*info = -13;
	    } else if (*ldx < MAX(1,*n)) {
		*info = -15;
	    }
	}
    }

    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("CPBSVX", &i__1);
	return 0;
    }

    if (equil) {

/*        Compute row and column scalings to equilibrate the matrix A. */

	cpbequ_(uplo, n, kd, &ab[ab_offset], ldab, &s[1], &scond, &amax, &
		infequ);
	if (infequ == 0) {

/*           Equilibrate the matrix. */

	    claqhb_(uplo, n, kd, &ab[ab_offset], ldab, &s[1], &scond, &amax, 
		    equed);
	    rcequ = lsame_(equed, "Y");
	}
    }

/*     Scale the right-hand side. */

    if (rcequ) {
	i__1 = *nrhs;
	for (j = 1; j <= i__1; ++j) {
	    i__2 = *n;
	    for (i__ = 1; i__ <= i__2; ++i__) {
		i__3 = i__ + j * b_dim1;
		i__4 = i__;
		i__5 = i__ + j * b_dim1;
		q__1.r = s[i__4] * b[i__5].r, q__1.i = s[i__4] * b[i__5].i;
		b[i__3].r = q__1.r, b[i__3].i = q__1.i;
/* L20: */
	    }
/* L30: */
	}
    }

    if (nofact || equil) {

/*        Compute the Cholesky factorization A = U'*U or A = L*L'. */

	if (upper) {
	    i__1 = *n;
	    for (j = 1; j <= i__1; ++j) {
/* Computing MAX */
		i__2 = j - *kd;
		j1 = MAX(i__2,1);
		i__2 = j - j1 + 1;
		ccopy_(&i__2, &ab[*kd + 1 - j + j1 + j * ab_dim1], &c__1, &
			afb[*kd + 1 - j + j1 + j * afb_dim1], &c__1);
/* L40: */
	    }
	} else {
	    i__1 = *n;
	    for (j = 1; j <= i__1; ++j) {
/* Computing MIN */
		i__2 = j + *kd;
		j2 = MIN(i__2,*n);
		i__2 = j2 - j + 1;
		ccopy_(&i__2, &ab[j * ab_dim1 + 1], &c__1, &afb[j * afb_dim1 
			+ 1], &c__1);
/* L50: */
	    }
	}

	cpbtrf_(uplo, n, kd, &afb[afb_offset], ldafb, info);

/*        Return if INFO is non-zero. */

	if (*info > 0) {
	    *rcond = 0.f;
	    return 0;
	}
    }

/*     Compute the norm of the matrix A. */

    anorm = clanhb_("1", uplo, n, kd, &ab[ab_offset], ldab, &rwork[1]);

/*     Compute the reciprocal of the condition number of A. */

    cpbcon_(uplo, n, kd, &afb[afb_offset], ldafb, &anorm, rcond, &work[1], &
	    rwork[1], info);

/*     Compute the solution matrix X. */

    clacpy_("Full", n, nrhs, &b[b_offset], ldb, &x[x_offset], ldx);
    cpbtrs_(uplo, n, kd, nrhs, &afb[afb_offset], ldafb, &x[x_offset], ldx, 
	    info);

/*     Use iterative refinement to improve the computed solution and */
/*     compute error bounds and backward error estimates for it. */

    cpbrfs_(uplo, n, kd, nrhs, &ab[ab_offset], ldab, &afb[afb_offset], ldafb, 
	    &b[b_offset], ldb, &x[x_offset], ldx, &ferr[1], &berr[1], &work[1]
, &rwork[1], info);

/*     Transform the solution matrix X to a solution of the original */
/*     system. */

    if (rcequ) {
	i__1 = *nrhs;
	for (j = 1; j <= i__1; ++j) {
	    i__2 = *n;
	    for (i__ = 1; i__ <= i__2; ++i__) {
		i__3 = i__ + j * x_dim1;
		i__4 = i__;
		i__5 = i__ + j * x_dim1;
		q__1.r = s[i__4] * x[i__5].r, q__1.i = s[i__4] * x[i__5].i;
		x[i__3].r = q__1.r, x[i__3].i = q__1.i;
/* L60: */
	    }
/* L70: */
	}
	i__1 = *nrhs;
	for (j = 1; j <= i__1; ++j) {
	    ferr[j] /= scond;
/* L80: */
	}
    }

/*     Set INFO = N+1 if the matrix is singular to working precision. */

    if (*rcond < slamch_("Epsilon")) {
	*info = *n + 1;
    }

    return 0;

/*     End of CPBSVX */

} /* cpbsvx_ */
Exemplo n.º 8
0
/* Subroutine */ int cpbt01_(char *uplo, integer *n, integer *kd, complex *a, 
	integer *lda, complex *afac, integer *ldafac, real *rwork, real *
	resid)
{
    /* System generated locals */
    integer a_dim1, a_offset, afac_dim1, afac_offset, i__1, i__2, i__3, i__4, 
	    i__5;
    complex q__1;

    /* Builtin functions */
    double r_imag(complex *);

    /* Local variables */
    integer i__, j, k, kc, ml, mu;
    real akk, eps;
    extern /* Subroutine */ int cher_(char *, integer *, real *, complex *, 
	    integer *, complex *, integer *);
    integer klen;
    extern /* Complex */ VOID cdotc_(complex *, integer *, complex *, integer 
	    *, complex *, integer *);
    extern logical lsame_(char *, char *);
    real anorm;
    extern /* Subroutine */ int ctrmv_(char *, char *, char *, integer *, 
	    complex *, integer *, complex *, integer *);
    extern doublereal clanhb_(char *, char *, integer *, integer *, complex *, 
	     integer *, real *), slamch_(char *);
    extern /* Subroutine */ int csscal_(integer *, real *, complex *, integer 
	    *);


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

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

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

/*  CPBT01 reconstructs a Hermitian positive definite band matrix A from */
/*  its L*L' or U'*U factorization and computes the residual */
/*     norm( L*L' - A ) / ( N * norm(A) * EPS ) or */
/*     norm( U'*U - A ) / ( N * norm(A) * EPS ), */
/*  where EPS is the machine epsilon, L' is the conjugate transpose of */
/*  L, and U' is the conjugate transpose of U. */

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

/*  UPLO    (input) CHARACTER*1 */
/*          Specifies whether the upper or lower triangular part of the */
/*          Hermitian matrix A is stored: */
/*          = 'U':  Upper triangular */
/*          = 'L':  Lower triangular */

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

/*  KD      (input) INTEGER */
/*          The number of super-diagonals of the matrix A if UPLO = 'U', */
/*          or the number of sub-diagonals if UPLO = 'L'.  KD >= 0. */

/*  A       (input) COMPLEX array, dimension (LDA,N) */
/*          The original Hermitian band matrix A.  If UPLO = 'U', the */
/*          upper triangular part of A is stored as a band matrix; if */
/*          UPLO = 'L', the lower triangular part of A is stored.  The */
/*          columns of the appropriate triangle are stored in the columns */
/*          of A and the diagonals of the triangle are stored in the rows */
/*          of A.  See CPBTRF for further details. */

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

/*  AFAC    (input) COMPLEX array, dimension (LDAFAC,N) */
/*          The factored form of the matrix A.  AFAC contains the factor */
/*          L or U from the L*L' or U'*U factorization in band storage */
/*          format, as computed by CPBTRF. */

/*  LDAFAC  (input) INTEGER */
/*          The leading dimension of the array AFAC. */
/*          LDAFAC >= max(1,KD+1). */

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

/*  RESID   (output) REAL */
/*          If UPLO = 'L', norm(L*L' - A) / ( N * norm(A) * EPS ) */
/*          If UPLO = 'U', norm(U'*U - A) / ( N * norm(A) * EPS ) */

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


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

/*     Quick exit if N = 0. */

    /* Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    afac_dim1 = *ldafac;
    afac_offset = 1 + afac_dim1;
    afac -= afac_offset;
    --rwork;

    /* Function Body */
    if (*n <= 0) {
	*resid = 0.f;
	return 0;
    }

/*     Exit with RESID = 1/EPS if ANORM = 0. */

    eps = slamch_("Epsilon");
    anorm = clanhb_("1", uplo, n, kd, &a[a_offset], lda, &rwork[1]);
    if (anorm <= 0.f) {
	*resid = 1.f / eps;
	return 0;
    }

/*     Check the imaginary parts of the diagonal elements and return with */
/*     an error code if any are nonzero. */

    if (lsame_(uplo, "U")) {
	i__1 = *n;
	for (j = 1; j <= i__1; ++j) {
	    if (r_imag(&afac[*kd + 1 + j * afac_dim1]) != 0.f) {
		*resid = 1.f / eps;
		return 0;
	    }
/* L10: */
	}
    } else {
	i__1 = *n;
	for (j = 1; j <= i__1; ++j) {
	    if (r_imag(&afac[j * afac_dim1 + 1]) != 0.f) {
		*resid = 1.f / eps;
		return 0;
	    }
/* L20: */
	}
    }

/*     Compute the product U'*U, overwriting U. */

    if (lsame_(uplo, "U")) {
	for (k = *n; k >= 1; --k) {
/* Computing MAX */
	    i__1 = 1, i__2 = *kd + 2 - k;
	    kc = max(i__1,i__2);
	    klen = *kd + 1 - kc;

/*           Compute the (K,K) element of the result. */

	    i__1 = klen + 1;
	    cdotc_(&q__1, &i__1, &afac[kc + k * afac_dim1], &c__1, &afac[kc + 
		    k * afac_dim1], &c__1);
	    akk = q__1.r;
	    i__1 = *kd + 1 + k * afac_dim1;
	    afac[i__1].r = akk, afac[i__1].i = 0.f;

/*           Compute the rest of column K. */

	    if (klen > 0) {
		i__1 = *ldafac - 1;
		ctrmv_("Upper", "Conjugate", "Non-unit", &klen, &afac[*kd + 1 
			+ (k - klen) * afac_dim1], &i__1, &afac[kc + k * 
			afac_dim1], &c__1);
	    }

/* L30: */
	}

/*     UPLO = 'L':  Compute the product L*L', overwriting L. */

    } else {
	for (k = *n; k >= 1; --k) {
/* Computing MIN */
	    i__1 = *kd, i__2 = *n - k;
	    klen = min(i__1,i__2);

/*           Add a multiple of column K of the factor L to each of */
/*           columns K+1 through N. */

	    if (klen > 0) {
		i__1 = *ldafac - 1;
		cher_("Lower", &klen, &c_b17, &afac[k * afac_dim1 + 2], &c__1, 
			 &afac[(k + 1) * afac_dim1 + 1], &i__1);
	    }

/*           Scale column K by the diagonal element. */

	    i__1 = k * afac_dim1 + 1;
	    akk = afac[i__1].r;
	    i__1 = klen + 1;
	    csscal_(&i__1, &akk, &afac[k * afac_dim1 + 1], &c__1);

/* L40: */
	}
    }

/*     Compute the difference  L*L' - A  or  U'*U - A. */

    if (lsame_(uplo, "U")) {
	i__1 = *n;
	for (j = 1; j <= i__1; ++j) {
/* Computing MAX */
	    i__2 = 1, i__3 = *kd + 2 - j;
	    mu = max(i__2,i__3);
	    i__2 = *kd + 1;
	    for (i__ = mu; i__ <= i__2; ++i__) {
		i__3 = i__ + j * afac_dim1;
		i__4 = i__ + j * afac_dim1;
		i__5 = i__ + j * a_dim1;
		q__1.r = afac[i__4].r - a[i__5].r, q__1.i = afac[i__4].i - a[
			i__5].i;
		afac[i__3].r = q__1.r, afac[i__3].i = q__1.i;
/* L50: */
	    }
/* L60: */
	}
    } else {
	i__1 = *n;
	for (j = 1; j <= i__1; ++j) {
/* Computing MIN */
	    i__2 = *kd + 1, i__3 = *n - j + 1;
	    ml = min(i__2,i__3);
	    i__2 = ml;
	    for (i__ = 1; i__ <= i__2; ++i__) {
		i__3 = i__ + j * afac_dim1;
		i__4 = i__ + j * afac_dim1;
		i__5 = i__ + j * a_dim1;
		q__1.r = afac[i__4].r - a[i__5].r, q__1.i = afac[i__4].i - a[
			i__5].i;
		afac[i__3].r = q__1.r, afac[i__3].i = q__1.i;
/* L70: */
	    }
/* L80: */
	}
    }

/*     Compute norm( L*L' - A ) / ( N * norm(A) * EPS ) */

    *resid = clanhb_("1", uplo, n, kd, &afac[afac_offset], ldafac, &rwork[1]);

    *resid = *resid / (real) (*n) / anorm / eps;

    return 0;

/*     End of CPBT01 */

} /* cpbt01_ */
Exemplo n.º 9
0
/* Subroutine */ int cpbt02_(char *uplo, integer *n, integer *kd, integer *
	nrhs, complex *a, integer *lda, complex *x, integer *ldx, complex *b, 
	integer *ldb, real *rwork, real *resid)
{
    /* System generated locals */
    integer a_dim1, a_offset, b_dim1, b_offset, x_dim1, x_offset, i__1;
    real r__1, r__2;
    complex q__1;

    /* Local variables */
    integer j;
    real eps;
    real anorm, bnorm, xnorm;


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

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

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

/*  CPBT02 computes the residual for a solution of a Hermitian banded */
/*  system of equations  A*x = b: */
/*     RESID = norm( B - A*X ) / ( norm(A) * norm(X) * EPS) */
/*  where EPS is the machine precision. */

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

/*  UPLO    (input) CHARACTER*1 */
/*          Specifies whether the upper or lower triangular part of the */
/*          Hermitian matrix A is stored: */
/*          = 'U':  Upper triangular */
/*          = 'L':  Lower triangular */

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

/*  KD      (input) INTEGER */
/*          The number of super-diagonals of the matrix A if UPLO = 'U', */
/*          or the number of sub-diagonals if UPLO = 'L'.  KD >= 0. */

/*  A       (input) COMPLEX array, dimension (LDA,N) */
/*          The original Hermitian band matrix A.  If UPLO = 'U', the */
/*          upper triangular part of A is stored as a band matrix; if */
/*          UPLO = 'L', the lower triangular part of A is stored.  The */
/*          columns of the appropriate triangle are stored in the columns */
/*          of A and the diagonals of the triangle are stored in the rows */
/*          of A.  See CPBTRF for further details. */

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

/*  X       (input) COMPLEX array, dimension (LDX,NRHS) */
/*          The computed solution vectors for the system of linear */
/*          equations. */

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

/*  B       (input/output) COMPLEX array, dimension (LDB,NRHS) */
/*          On entry, the right hand side vectors for the system of */
/*          linear equations. */
/*          On exit, B is overwritten with the difference B - A*X. */

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

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

/*  RESID   (output) REAL */
/*          The maximum over the number of right hand sides of */
/*          norm(B - A*X) / ( norm(A) * norm(X) * EPS ). */

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

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

/*     Quick exit if N = 0 or NRHS = 0. */

    /* Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    x_dim1 = *ldx;
    x_offset = 1 + x_dim1;
    x -= x_offset;
    b_dim1 = *ldb;
    b_offset = 1 + b_dim1;
    b -= b_offset;
    --rwork;

    /* Function Body */
    if (*n <= 0 || *nrhs <= 0) {
	*resid = 0.f;
	return 0;
    }

/*     Exit with RESID = 1/EPS if ANORM = 0. */

    eps = slamch_("Epsilon");
    anorm = clanhb_("1", uplo, n, kd, &a[a_offset], lda, &rwork[1]);
    if (anorm <= 0.f) {
	*resid = 1.f / eps;
	return 0;
    }

/*     Compute  B - A*X */

    i__1 = *nrhs;
    for (j = 1; j <= i__1; ++j) {
	q__1.r = -1.f, q__1.i = -0.f;
	chbmv_(uplo, n, kd, &q__1, &a[a_offset], lda, &x[j * x_dim1 + 1], &
		c__1, &c_b1, &b[j * b_dim1 + 1], &c__1);
/* L10: */
    }

/*     Compute the maximum over the number of right hand sides of */
/*          norm( B - A*X ) / ( norm(A) * norm(X) * EPS ) */

    *resid = 0.f;
    i__1 = *nrhs;
    for (j = 1; j <= i__1; ++j) {
	bnorm = scasum_(n, &b[j * b_dim1 + 1], &c__1);
	xnorm = scasum_(n, &x[j * x_dim1 + 1], &c__1);
	if (xnorm <= 0.f) {
	    *resid = 1.f / eps;
	} else {
/* Computing MAX */
	    r__1 = *resid, r__2 = bnorm / anorm / xnorm / eps;
	    *resid = dmax(r__1,r__2);
	}
/* L20: */
    }

    return 0;

/*     End of CPBT02 */

} /* cpbt02_ */
Exemplo n.º 10
0
/* Subroutine */ int chbevd_(char *jobz, char *uplo, integer *n, integer *kd, 
	complex *ab, integer *ldab, real *w, complex *z__, integer *ldz, 
	complex *work, integer *lwork, real *rwork, integer *lrwork, integer *
	iwork, integer *liwork, integer *info)
{
    /* System generated locals */
    integer ab_dim1, ab_offset, z_dim1, z_offset, i__1;
    real r__1;

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

    /* Local variables */
    real eps;
    integer inde;
    real anrm;
    integer imax;
    real rmin, rmax;
    integer llwk2;
    extern /* Subroutine */ int cgemm_(char *, char *, integer *, integer *, 
	    integer *, complex *, complex *, integer *, complex *, integer *, 
	    complex *, complex *, integer *);
    real sigma;
    extern logical lsame_(char *, char *);
    integer iinfo;
    extern /* Subroutine */ int sscal_(integer *, real *, real *, integer *);
    integer lwmin;
    logical lower;
    integer llrwk;
    logical wantz;
    integer indwk2;
    extern doublereal clanhb_(char *, char *, integer *, integer *, complex *, 
	     integer *, real *);
    integer iscale;
    extern /* Subroutine */ int clascl_(char *, integer *, integer *, real *, 
	    real *, integer *, integer *, complex *, integer *, integer *), cstedc_(char *, integer *, real *, real *, complex *, 
	    integer *, complex *, integer *, real *, integer *, integer *, 
	    integer *, integer *), chbtrd_(char *, char *, integer *, 
	    integer *, complex *, integer *, real *, real *, complex *, 
	    integer *, complex *, integer *);
    extern doublereal slamch_(char *);
    extern /* Subroutine */ int clacpy_(char *, integer *, integer *, complex 
	    *, integer *, complex *, integer *);
    real safmin;
    extern /* Subroutine */ int xerbla_(char *, integer *);
    real bignum;
    integer indwrk, liwmin;
    extern /* Subroutine */ int ssterf_(integer *, real *, real *, integer *);
    integer lrwmin;
    real smlnum;
    logical lquery;


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

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

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

/*  CHBEVD computes all the eigenvalues and, optionally, eigenvectors of */
/*  a complex Hermitian band matrix A.  If eigenvectors are desired, it */
/*  uses a divide and conquer algorithm. */

/*  The divide and conquer algorithm makes very mild assumptions about */
/*  floating point arithmetic. It will work on machines with a guard */
/*  digit in add/subtract, or on those binary machines without guard */
/*  digits which subtract like the Cray X-MP, Cray Y-MP, Cray C-90, or */
/*  Cray-2. It could conceivably fail on hexadecimal or decimal machines */
/*  without guard digits, but we know of none. */

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

/*  JOBZ    (input) CHARACTER*1 */
/*          = 'N':  Compute eigenvalues only; */
/*          = 'V':  Compute eigenvalues and eigenvectors. */

/*  UPLO    (input) CHARACTER*1 */
/*          = 'U':  Upper triangle of A is stored; */
/*          = 'L':  Lower triangle of A is stored. */

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

/*  KD      (input) INTEGER */
/*          The number of superdiagonals of the matrix A if UPLO = 'U', */
/*          or the number of subdiagonals if UPLO = 'L'.  KD >= 0. */

/*  AB      (input/output) COMPLEX array, dimension (LDAB, N) */
/*          On entry, the upper or lower triangle of the Hermitian band */
/*          matrix A, stored in the first KD+1 rows of the array.  The */
/*          j-th column of A is stored in the j-th column of the array AB */
/*          as follows: */
/*          if UPLO = 'U', AB(kd+1+i-j,j) = A(i,j) for max(1,j-kd)<=i<=j; */
/*          if UPLO = 'L', AB(1+i-j,j)    = A(i,j) for j<=i<=min(n,j+kd). */

/*          On exit, AB is overwritten by values generated during the */
/*          reduction to tridiagonal form.  If UPLO = 'U', the first */
/*          superdiagonal and the diagonal of the tridiagonal matrix T */
/*          are returned in rows KD and KD+1 of AB, and if UPLO = 'L', */
/*          the diagonal and first subdiagonal of T are returned in the */
/*          first two rows of AB. */

/*  LDAB    (input) INTEGER */
/*          The leading dimension of the array AB.  LDAB >= KD + 1. */

/*  W       (output) REAL array, dimension (N) */
/*          If INFO = 0, the eigenvalues in ascending order. */

/*  Z       (output) COMPLEX array, dimension (LDZ, N) */
/*          If JOBZ = 'V', then if INFO = 0, Z contains the orthonormal */
/*          eigenvectors of the matrix A, with the i-th column of Z */
/*          holding the eigenvector associated with W(i). */
/*          If JOBZ = 'N', then Z is not referenced. */

/*  LDZ     (input) INTEGER */
/*          The leading dimension of the array Z.  LDZ >= 1, and if */
/*          JOBZ = 'V', LDZ >= max(1,N). */

/*  WORK    (workspace/output) COMPLEX array, dimension (MAX(1,LWORK)) */
/*          On exit, if INFO = 0, WORK(1) returns the optimal LWORK. */

/*  LWORK   (input) INTEGER */
/*          The dimension of the array WORK. */
/*          If N <= 1,               LWORK must be at least 1. */
/*          If JOBZ = 'N' and N > 1, LWORK must be at least N. */
/*          If JOBZ = 'V' and N > 1, LWORK must be at least 2*N**2. */

/*          If LWORK = -1, then a workspace query is assumed; the routine */
/*          only calculates the optimal sizes of the WORK, RWORK and */
/*          IWORK arrays, returns these values as the first entries of */
/*          the WORK, RWORK and IWORK arrays, and no error message */
/*          related to LWORK or LRWORK or LIWORK is issued by XERBLA. */

/*  RWORK   (workspace/output) REAL array, */
/*                                         dimension (LRWORK) */
/*          On exit, if INFO = 0, RWORK(1) returns the optimal LRWORK. */

/*  LRWORK  (input) INTEGER */
/*          The dimension of array RWORK. */
/*          If N <= 1,               LRWORK must be at least 1. */
/*          If JOBZ = 'N' and N > 1, LRWORK must be at least N. */
/*          If JOBZ = 'V' and N > 1, LRWORK must be at least */
/*                        1 + 5*N + 2*N**2. */

/*          If LRWORK = -1, then a workspace query is assumed; the */
/*          routine only calculates the optimal sizes of the WORK, RWORK */
/*          and IWORK arrays, returns these values as the first entries */
/*          of the WORK, RWORK and IWORK arrays, and no error message */
/*          related to LWORK or LRWORK or LIWORK is issued by XERBLA. */

/*  IWORK   (workspace/output) INTEGER array, dimension (MAX(1,LIWORK)) */
/*          On exit, if INFO = 0, IWORK(1) returns the optimal LIWORK. */

/*  LIWORK  (input) INTEGER */
/*          The dimension of array IWORK. */
/*          If JOBZ = 'N' or N <= 1, LIWORK must be at least 1. */
/*          If JOBZ = 'V' and N > 1, LIWORK must be at least 3 + 5*N . */

/*          If LIWORK = -1, then a workspace query is assumed; the */
/*          routine only calculates the optimal sizes of the WORK, RWORK */
/*          and IWORK arrays, returns these values as the first entries */
/*          of the WORK, RWORK and IWORK arrays, and no error message */
/*          related to LWORK or LRWORK or LIWORK is issued by XERBLA. */

/*  INFO    (output) INTEGER */
/*          = 0:  successful exit. */
/*          < 0:  if INFO = -i, the i-th argument had an illegal value. */
/*          > 0:  if INFO = i, the algorithm failed to converge; i */
/*                off-diagonal elements of an intermediate tridiagonal */
/*                form did not converge to zero. */

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

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

/*     Test the input parameters. */

    /* Parameter adjustments */
    ab_dim1 = *ldab;
    ab_offset = 1 + ab_dim1;
    ab -= ab_offset;
    --w;
    z_dim1 = *ldz;
    z_offset = 1 + z_dim1;
    z__ -= z_offset;
    --work;
    --rwork;
    --iwork;

    /* Function Body */
    wantz = lsame_(jobz, "V");
    lower = lsame_(uplo, "L");
    lquery = *lwork == -1 || *liwork == -1 || *lrwork == -1;

    *info = 0;
    if (*n <= 1) {
	lwmin = 1;
	lrwmin = 1;
	liwmin = 1;
    } else {
	if (wantz) {
/* Computing 2nd power */
	    i__1 = *n;
	    lwmin = i__1 * i__1 << 1;
/* Computing 2nd power */
	    i__1 = *n;
	    lrwmin = *n * 5 + 1 + (i__1 * i__1 << 1);
	    liwmin = *n * 5 + 3;
	} else {
	    lwmin = *n;
	    lrwmin = *n;
	    liwmin = 1;
	}
    }
    if (! (wantz || lsame_(jobz, "N"))) {
	*info = -1;
    } else if (! (lower || lsame_(uplo, "U"))) {
	*info = -2;
    } else if (*n < 0) {
	*info = -3;
    } else if (*kd < 0) {
	*info = -4;
    } else if (*ldab < *kd + 1) {
	*info = -6;
    } else if (*ldz < 1 || wantz && *ldz < *n) {
	*info = -9;
    }

    if (*info == 0) {
	work[1].r = (real) lwmin, work[1].i = 0.f;
	rwork[1] = (real) lrwmin;
	iwork[1] = liwmin;

	if (*lwork < lwmin && ! lquery) {
	    *info = -11;
	} else if (*lrwork < lrwmin && ! lquery) {
	    *info = -13;
	} else if (*liwork < liwmin && ! lquery) {
	    *info = -15;
	}
    }

    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("CHBEVD", &i__1);
	return 0;
    } else if (lquery) {
	return 0;
    }

/*     Quick return if possible */

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

    if (*n == 1) {
	i__1 = ab_dim1 + 1;
	w[1] = ab[i__1].r;
	if (wantz) {
	    i__1 = z_dim1 + 1;
	    z__[i__1].r = 1.f, z__[i__1].i = 0.f;
	}
	return 0;
    }

/*     Get machine constants. */

    safmin = slamch_("Safe minimum");
    eps = slamch_("Precision");
    smlnum = safmin / eps;
    bignum = 1.f / smlnum;
    rmin = sqrt(smlnum);
    rmax = sqrt(bignum);

/*     Scale matrix to allowable range, if necessary. */

    anrm = clanhb_("M", uplo, n, kd, &ab[ab_offset], ldab, &rwork[1]);
    iscale = 0;
    if (anrm > 0.f && anrm < rmin) {
	iscale = 1;
	sigma = rmin / anrm;
    } else if (anrm > rmax) {
	iscale = 1;
	sigma = rmax / anrm;
    }
    if (iscale == 1) {
	if (lower) {
	    clascl_("B", kd, kd, &c_b13, &sigma, n, n, &ab[ab_offset], ldab, 
		    info);
	} else {
	    clascl_("Q", kd, kd, &c_b13, &sigma, n, n, &ab[ab_offset], ldab, 
		    info);
	}
    }

/*     Call CHBTRD to reduce Hermitian band matrix to tridiagonal form. */

    inde = 1;
    indwrk = inde + *n;
    indwk2 = *n * *n + 1;
    llwk2 = *lwork - indwk2 + 1;
    llrwk = *lrwork - indwrk + 1;
    chbtrd_(jobz, uplo, n, kd, &ab[ab_offset], ldab, &w[1], &rwork[inde], &
	    z__[z_offset], ldz, &work[1], &iinfo);

/*     For eigenvalues only, call SSTERF.  For eigenvectors, call CSTEDC. */

    if (! wantz) {
	ssterf_(n, &w[1], &rwork[inde], info);
    } else {
	cstedc_("I", n, &w[1], &rwork[inde], &work[1], n, &work[indwk2], &
		llwk2, &rwork[indwrk], &llrwk, &iwork[1], liwork, info);
	cgemm_("N", "N", n, n, n, &c_b2, &z__[z_offset], ldz, &work[1], n, &
		c_b1, &work[indwk2], n);
	clacpy_("A", n, n, &work[indwk2], n, &z__[z_offset], ldz);
    }

/*     If matrix was scaled, then rescale eigenvalues appropriately. */

    if (iscale == 1) {
	if (*info == 0) {
	    imax = *n;
	} else {
	    imax = *info - 1;
	}
	r__1 = 1.f / sigma;
	sscal_(&imax, &r__1, &w[1], &c__1);
    }

    work[1].r = (real) lwmin, work[1].i = 0.f;
    rwork[1] = (real) lrwmin;
    iwork[1] = liwmin;
    return 0;

/*     End of CHBEVD */

} /* chbevd_ */