Пример #1
0
/* Subroutine */ int csyrfs_(char *uplo, integer *n, integer *nrhs, complex *
	a, integer *lda, complex *af, integer *ldaf, integer *ipiv, complex *
	b, integer *ldb, complex *x, integer *ldx, real *ferr, real *berr, 
	complex *work, real *rwork, integer *info)
{
    /* System generated locals */
    integer a_dim1, a_offset, af_dim1, af_offset, b_dim1, b_offset, x_dim1, 
	    x_offset, i__1, i__2, i__3, i__4, i__5;
    real r__1, r__2, r__3, r__4;
    complex q__1;

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

    /* Local variables */
    integer i__, j, k;
    real s, xk;
    integer nz;
    real eps;
    integer kase;
    real safe1, safe2;
    extern logical lsame_(char *, char *);
    integer isave[3];
    extern /* Subroutine */ int ccopy_(integer *, complex *, integer *, 
	    complex *, integer *), caxpy_(integer *, complex *, complex *, 
	    integer *, complex *, integer *);
    integer count;
    logical upper;
    extern /* Subroutine */ int csymv_(char *, integer *, complex *, complex *
, integer *, complex *, integer *, complex *, complex *, integer *
), clacn2_(integer *, complex *, complex *, real *, 
	    integer *, integer *);
    extern doublereal slamch_(char *);
    real safmin;
    extern /* Subroutine */ int xerbla_(char *, integer *);
    real lstres;
    extern /* Subroutine */ int csytrs_(char *, integer *, integer *, complex 
	    *, integer *, integer *, complex *, integer *, integer *);


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

/*     Modified to call CLACN2 in place of CLACON, 10 Feb 03, SJH. */

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

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

/*  CSYRFS improves the computed solution to a system of linear */
/*  equations when the coefficient matrix is symmetric indefinite, and */
/*  provides error bounds and backward error estimates for the solution. */

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

/*  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. */

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

/*  A       (input) COMPLEX array, dimension (LDA,N) */
/*          The symmetric matrix A.  If UPLO = 'U', the leading N-by-N */
/*          upper triangular part of A contains the upper triangular part */
/*          of the matrix A, and the strictly lower triangular part of A */
/*          is not referenced.  If UPLO = 'L', the leading N-by-N lower */
/*          triangular part of A contains the lower triangular part of */
/*          the matrix A, and the strictly upper triangular part of A is */
/*          not referenced. */

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

/*  AF      (input) COMPLEX array, dimension (LDAF,N) */
/*          The factored form of the matrix A.  AF contains the block */
/*          diagonal matrix D and the multipliers used to obtain the */
/*          factor U or L from the factorization A = U*D*U**T or */
/*          A = L*D*L**T as computed by CSYTRF. */

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

/*  IPIV    (input) INTEGER array, dimension (N) */
/*          Details of the interchanges and the block structure of D */
/*          as determined by CSYTRF. */

/*  B       (input) COMPLEX array, dimension (LDB,NRHS) */
/*          The right hand side matrix B. */

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

/*  X       (input/output) COMPLEX array, dimension (LDX,NRHS) */
/*          On entry, the solution matrix X, as computed by CSYTRS. */
/*          On exit, the improved solution matrix X. */

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

/*  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 */

/*  Internal Parameters */
/*  =================== */

/*  ITMAX is the maximum number of steps of iterative refinement. */

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

/*     .. Parameters .. */
/*     .. */
/*     .. Local Scalars .. */
/*     .. */
/*     .. Local Arrays .. */
/*     .. */
/*     .. External Subroutines .. */
/*     .. */
/*     .. Intrinsic Functions .. */
/*     .. */
/*     .. External Functions .. */
/*     .. */
/*     .. Statement Functions .. */
/*     .. */
/*     .. Statement Function definitions .. */
/*     .. */
/*     .. Executable Statements .. */

/*     Test the input parameters. */

    /* Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    af_dim1 = *ldaf;
    af_offset = 1 + af_dim1;
    af -= af_offset;
    --ipiv;
    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;
    upper = lsame_(uplo, "U");
    if (! upper && ! lsame_(uplo, "L")) {
	*info = -1;
    } else if (*n < 0) {
	*info = -2;
    } else if (*nrhs < 0) {
	*info = -3;
    } else if (*lda < max(1,*n)) {
	*info = -5;
    } else if (*ldaf < max(1,*n)) {
	*info = -7;
    } else if (*ldb < max(1,*n)) {
	*info = -10;
    } else if (*ldx < max(1,*n)) {
	*info = -12;
    }
    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("CSYRFS", &i__1);
	return 0;
    }

/*     Quick return if possible */

    if (*n == 0 || *nrhs == 0) {
	i__1 = *nrhs;
	for (j = 1; j <= i__1; ++j) {
	    ferr[j] = 0.f;
	    berr[j] = 0.f;
/* L10: */
	}
	return 0;
    }

/*     NZ = maximum number of nonzero elements in each row of A, plus 1 */

    nz = *n + 1;
    eps = slamch_("Epsilon");
    safmin = slamch_("Safe minimum");
    safe1 = nz * safmin;
    safe2 = safe1 / eps;

/*     Do for each right hand side */

    i__1 = *nrhs;
    for (j = 1; j <= i__1; ++j) {

	count = 1;
	lstres = 3.f;
L20:

/*        Loop until stopping criterion is satisfied. */

/*        Compute residual R = B - A * X */

	ccopy_(n, &b[j * b_dim1 + 1], &c__1, &work[1], &c__1);
	q__1.r = -1.f, q__1.i = -0.f;
	csymv_(uplo, n, &q__1, &a[a_offset], lda, &x[j * x_dim1 + 1], &c__1, &
		c_b1, &work[1], &c__1);

/*        Compute componentwise relative backward error from formula */

/*        max(i) ( abs(R(i)) / ( abs(A)*abs(X) + abs(B) )(i) ) */

/*        where abs(Z) is the componentwise absolute value of the matrix */
/*        or vector Z.  If the i-th component of the denominator is less */
/*        than SAFE2, then SAFE1 is added to the i-th components of the */
/*        numerator and denominator before dividing. */

	i__2 = *n;
	for (i__ = 1; i__ <= i__2; ++i__) {
	    i__3 = i__ + j * b_dim1;
	    rwork[i__] = (r__1 = b[i__3].r, dabs(r__1)) + (r__2 = r_imag(&b[
		    i__ + j * b_dim1]), dabs(r__2));
/* L30: */
	}

/*        Compute abs(A)*abs(X) + abs(B). */

	if (upper) {
	    i__2 = *n;
	    for (k = 1; k <= i__2; ++k) {
		s = 0.f;
		i__3 = k + j * x_dim1;
		xk = (r__1 = x[i__3].r, dabs(r__1)) + (r__2 = r_imag(&x[k + j 
			* x_dim1]), dabs(r__2));
		i__3 = k - 1;
		for (i__ = 1; i__ <= i__3; ++i__) {
		    i__4 = i__ + k * a_dim1;
		    rwork[i__] += ((r__1 = a[i__4].r, dabs(r__1)) + (r__2 = 
			    r_imag(&a[i__ + k * a_dim1]), dabs(r__2))) * xk;
		    i__4 = i__ + k * a_dim1;
		    i__5 = i__ + j * x_dim1;
		    s += ((r__1 = a[i__4].r, dabs(r__1)) + (r__2 = r_imag(&a[
			    i__ + k * a_dim1]), dabs(r__2))) * ((r__3 = x[
			    i__5].r, dabs(r__3)) + (r__4 = r_imag(&x[i__ + j *
			     x_dim1]), dabs(r__4)));
/* L40: */
		}
		i__3 = k + k * a_dim1;
		rwork[k] = rwork[k] + ((r__1 = a[i__3].r, dabs(r__1)) + (r__2 
			= r_imag(&a[k + k * a_dim1]), dabs(r__2))) * xk + s;
/* L50: */
	    }
	} else {
	    i__2 = *n;
	    for (k = 1; k <= i__2; ++k) {
		s = 0.f;
		i__3 = k + j * x_dim1;
		xk = (r__1 = x[i__3].r, dabs(r__1)) + (r__2 = r_imag(&x[k + j 
			* x_dim1]), dabs(r__2));
		i__3 = k + k * a_dim1;
		rwork[k] += ((r__1 = a[i__3].r, dabs(r__1)) + (r__2 = r_imag(&
			a[k + k * a_dim1]), dabs(r__2))) * xk;
		i__3 = *n;
		for (i__ = k + 1; i__ <= i__3; ++i__) {
		    i__4 = i__ + k * a_dim1;
		    rwork[i__] += ((r__1 = a[i__4].r, dabs(r__1)) + (r__2 = 
			    r_imag(&a[i__ + k * a_dim1]), dabs(r__2))) * xk;
		    i__4 = i__ + k * a_dim1;
		    i__5 = i__ + j * x_dim1;
		    s += ((r__1 = a[i__4].r, dabs(r__1)) + (r__2 = r_imag(&a[
			    i__ + k * a_dim1]), dabs(r__2))) * ((r__3 = x[
			    i__5].r, dabs(r__3)) + (r__4 = r_imag(&x[i__ + j *
			     x_dim1]), dabs(r__4)));
/* L60: */
		}
		rwork[k] += s;
/* L70: */
	    }
	}
	s = 0.f;
	i__2 = *n;
	for (i__ = 1; i__ <= i__2; ++i__) {
	    if (rwork[i__] > safe2) {
/* Computing MAX */
		i__3 = i__;
		r__3 = s, r__4 = ((r__1 = work[i__3].r, dabs(r__1)) + (r__2 = 
			r_imag(&work[i__]), dabs(r__2))) / rwork[i__];
		s = dmax(r__3,r__4);
	    } else {
/* Computing MAX */
		i__3 = i__;
		r__3 = s, r__4 = ((r__1 = work[i__3].r, dabs(r__1)) + (r__2 = 
			r_imag(&work[i__]), dabs(r__2)) + safe1) / (rwork[i__]
			 + safe1);
		s = dmax(r__3,r__4);
	    }
/* L80: */
	}
	berr[j] = s;

/*        Test stopping criterion. Continue iterating if */
/*           1) The residual BERR(J) is larger than machine epsilon, and */
/*           2) BERR(J) decreased by at least a factor of 2 during the */
/*              last iteration, and */
/*           3) At most ITMAX iterations tried. */

	if (berr[j] > eps && berr[j] * 2.f <= lstres && count <= 5) {

/*           Update solution and try again. */

	    csytrs_(uplo, n, &c__1, &af[af_offset], ldaf, &ipiv[1], &work[1], 
		    n, info);
	    caxpy_(n, &c_b1, &work[1], &c__1, &x[j * x_dim1 + 1], &c__1);
	    lstres = berr[j];
	    ++count;
	    goto L20;
	}

/*        Bound error from formula */

/*        norm(X - XTRUE) / norm(X) .le. FERR = */
/*        norm( abs(inv(A))* */
/*           ( abs(R) + NZ*EPS*( abs(A)*abs(X)+abs(B) ))) / norm(X) */

/*        where */
/*          norm(Z) is the magnitude of the largest component of Z */
/*          inv(A) is the inverse of A */
/*          abs(Z) is the componentwise absolute value of the matrix or */
/*             vector Z */
/*          NZ is the maximum number of nonzeros in any row of A, plus 1 */
/*          EPS is machine epsilon */

/*        The i-th component of abs(R)+NZ*EPS*(abs(A)*abs(X)+abs(B)) */
/*        is incremented by SAFE1 if the i-th component of */
/*        abs(A)*abs(X) + abs(B) is less than SAFE2. */

/*        Use CLACN2 to estimate the infinity-norm of the matrix */
/*           inv(A) * diag(W), */
/*        where W = abs(R) + NZ*EPS*( abs(A)*abs(X)+abs(B) ))) */

	i__2 = *n;
	for (i__ = 1; i__ <= i__2; ++i__) {
	    if (rwork[i__] > safe2) {
		i__3 = i__;
		rwork[i__] = (r__1 = work[i__3].r, dabs(r__1)) + (r__2 = 
			r_imag(&work[i__]), dabs(r__2)) + nz * eps * rwork[
			i__];
	    } else {
		i__3 = i__;
		rwork[i__] = (r__1 = work[i__3].r, dabs(r__1)) + (r__2 = 
			r_imag(&work[i__]), dabs(r__2)) + nz * eps * rwork[
			i__] + safe1;
	    }
/* L90: */
	}

	kase = 0;
L100:
	clacn2_(n, &work[*n + 1], &work[1], &ferr[j], &kase, isave);
	if (kase != 0) {
	    if (kase == 1) {

/*              Multiply by diag(W)*inv(A'). */

		csytrs_(uplo, n, &c__1, &af[af_offset], ldaf, &ipiv[1], &work[
			1], n, info);
		i__2 = *n;
		for (i__ = 1; i__ <= i__2; ++i__) {
		    i__3 = i__;
		    i__4 = i__;
		    i__5 = i__;
		    q__1.r = rwork[i__4] * work[i__5].r, q__1.i = rwork[i__4] 
			    * work[i__5].i;
		    work[i__3].r = q__1.r, work[i__3].i = q__1.i;
/* L110: */
		}
	    } else if (kase == 2) {

/*              Multiply by inv(A)*diag(W). */

		i__2 = *n;
		for (i__ = 1; i__ <= i__2; ++i__) {
		    i__3 = i__;
		    i__4 = i__;
		    i__5 = i__;
		    q__1.r = rwork[i__4] * work[i__5].r, q__1.i = rwork[i__4] 
			    * work[i__5].i;
		    work[i__3].r = q__1.r, work[i__3].i = q__1.i;
/* L120: */
		}
		csytrs_(uplo, n, &c__1, &af[af_offset], ldaf, &ipiv[1], &work[
			1], n, info);
	    }
	    goto L100;
	}

/*        Normalize error. */

	lstres = 0.f;
	i__2 = *n;
	for (i__ = 1; i__ <= i__2; ++i__) {
/* Computing MAX */
	    i__3 = i__ + j * x_dim1;
	    r__3 = lstres, r__4 = (r__1 = x[i__3].r, dabs(r__1)) + (r__2 = 
		    r_imag(&x[i__ + j * x_dim1]), dabs(r__2));
	    lstres = dmax(r__3,r__4);
/* L130: */
	}
	if (lstres != 0.f) {
	    ferr[j] /= lstres;
	}

/* L140: */
    }

    return 0;

/*     End of CSYRFS */

} /* csyrfs_ */
Пример #2
0
/* Subroutine */
int cla_syrfsx_extended_(integer *prec_type__, char *uplo, integer *n, integer *nrhs, complex *a, integer *lda, complex *af, integer *ldaf, integer *ipiv, logical *colequ, real *c__, complex *b, integer *ldb, complex *y, integer *ldy, real *berr_out__, integer * n_norms__, real *err_bnds_norm__, real *err_bnds_comp__, complex *res, real *ayb, complex *dy, complex *y_tail__, real *rcond, integer * ithresh, real *rthresh, real *dz_ub__, logical *ignore_cwise__, integer *info)
{
    /* System generated locals */
    integer a_dim1, a_offset, af_dim1, af_offset, b_dim1, b_offset, y_dim1, y_offset, err_bnds_norm_dim1, err_bnds_norm_offset, err_bnds_comp_dim1, err_bnds_comp_offset, i__1, i__2, i__3, i__4;
    real r__1, r__2;
    /* Builtin functions */
    double r_imag(complex *);
    /* Local variables */
    real dxratmax, dzratmax;
    integer i__, j;
    logical incr_prec__;
    extern /* Subroutine */
    int cla_syamv_(integer *, integer *, real *, complex *, integer *, complex *, integer *, real *, real *, integer *);
    real prev_dz_z__, yk, final_dx_x__;
    extern /* Subroutine */
    int cla_wwaddw_(integer *, complex *, complex *, complex *);
    real final_dz_z__, prevnormdx;
    integer cnt;
    real dyk, eps, incr_thresh__, dx_x__, dz_z__;
    extern /* Subroutine */
    int cla_lin_berr_(integer *, integer *, integer * , complex *, real *, real *);
    real ymin;
    integer y_prec_state__;
    extern /* Subroutine */
    int blas_csymv_x_(integer *, integer *, complex * , complex *, integer *, complex *, integer *, complex *, complex * , integer *, integer *);
    integer uplo2;
    extern logical lsame_(char *, char *);
    extern /* Subroutine */
    int blas_csymv2_x_(integer *, integer *, complex *, complex *, integer *, complex *, complex *, integer *, complex *, complex *, integer *, integer *), ccopy_(integer *, complex *, integer *, complex *, integer *);
    real dxrat, dzrat;
    extern /* Subroutine */
    int caxpy_(integer *, complex *, complex *, integer *, complex *, integer *);
    logical upper;
    extern /* Subroutine */
    int csymv_(char *, integer *, complex *, complex * , integer *, complex *, integer *, complex *, complex *, integer * );
    real normx, normy;
    extern real slamch_(char *);
    extern /* Subroutine */
    int xerbla_(char *, integer *);
    real normdx;
    extern /* Subroutine */
    int csytrs_(char *, integer *, integer *, complex *, integer *, integer *, complex *, integer *, integer *);
    real hugeval;
    extern integer ilauplo_(char *);
    integer x_state__, z_state__;
    /* -- LAPACK computational routine (version 3.4.2) -- */
    /* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
    /* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
    /* September 2012 */
    /* .. Scalar Arguments .. */
    /* .. */
    /* .. Array Arguments .. */
    /* .. */
    /* ===================================================================== */
    /* .. Local Scalars .. */
    /* .. */
    /* .. Parameters .. */
    /* .. */
    /* .. External Functions .. */
    /* .. */
    /* .. External Subroutines .. */
    /* .. */
    /* .. Intrinsic Functions .. */
    /* .. */
    /* .. Statement Functions .. */
    /* .. */
    /* .. Statement Function Definitions .. */
    /* .. */
    /* .. Executable Statements .. */
    /* Parameter adjustments */
    err_bnds_comp_dim1 = *nrhs;
    err_bnds_comp_offset = 1 + err_bnds_comp_dim1;
    err_bnds_comp__ -= err_bnds_comp_offset;
    err_bnds_norm_dim1 = *nrhs;
    err_bnds_norm_offset = 1 + err_bnds_norm_dim1;
    err_bnds_norm__ -= err_bnds_norm_offset;
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    af_dim1 = *ldaf;
    af_offset = 1 + af_dim1;
    af -= af_offset;
    --ipiv;
    --c__;
    b_dim1 = *ldb;
    b_offset = 1 + b_dim1;
    b -= b_offset;
    y_dim1 = *ldy;
    y_offset = 1 + y_dim1;
    y -= y_offset;
    --berr_out__;
    --res;
    --ayb;
    --dy;
    --y_tail__;
    /* Function Body */
    *info = 0;
    upper = lsame_(uplo, "U");
    if (! upper && ! lsame_(uplo, "L"))
    {
        *info = -2;
    }
    else if (*n < 0)
    {
        *info = -3;
    }
    else if (*nrhs < 0)
    {
        *info = -4;
    }
    else if (*lda < max(1,*n))
    {
        *info = -6;
    }
    else if (*ldaf < max(1,*n))
    {
        *info = -8;
    }
    else if (*ldb < max(1,*n))
    {
        *info = -13;
    }
    else if (*ldy < max(1,*n))
    {
        *info = -15;
    }
    if (*info != 0)
    {
        i__1 = -(*info);
        xerbla_("CLA_SYRFSX_EXTENDED", &i__1);
        return 0;
    }
    eps = slamch_("Epsilon");
    hugeval = slamch_("Overflow");
    /* Force HUGEVAL to Inf */
    hugeval *= hugeval;
    /* Using HUGEVAL may lead to spurious underflows. */
    incr_thresh__ = (real) (*n) * eps;
    if (lsame_(uplo, "L"))
    {
        uplo2 = ilauplo_("L");
    }
    else
    {
        uplo2 = ilauplo_("U");
    }
    i__1 = *nrhs;
    for (j = 1;
            j <= i__1;
            ++j)
    {
        y_prec_state__ = 1;
        if (y_prec_state__ == 2)
        {
            i__2 = *n;
            for (i__ = 1;
                    i__ <= i__2;
                    ++i__)
            {
                i__3 = i__;
                y_tail__[i__3].r = 0.f;
                y_tail__[i__3].i = 0.f; // , expr subst
            }
        }
        dxrat = 0.f;
        dxratmax = 0.f;
        dzrat = 0.f;
        dzratmax = 0.f;
        final_dx_x__ = hugeval;
        final_dz_z__ = hugeval;
        prevnormdx = hugeval;
        prev_dz_z__ = hugeval;
        dz_z__ = hugeval;
        dx_x__ = hugeval;
        x_state__ = 1;
        z_state__ = 0;
        incr_prec__ = FALSE_;
        i__2 = *ithresh;
        for (cnt = 1;
                cnt <= i__2;
                ++cnt)
        {
            /* Compute residual RES = B_s - op(A_s) * Y, */
            /* op(A) = A, A**T, or A**H depending on TRANS (and type). */
            ccopy_(n, &b[j * b_dim1 + 1], &c__1, &res[1], &c__1);
            if (y_prec_state__ == 0)
            {
                csymv_(uplo, n, &c_b14, &a[a_offset], lda, &y[j * y_dim1 + 1], &c__1, &c_b15, &res[1], &c__1);
            }
            else if (y_prec_state__ == 1)
            {
                blas_csymv_x_(&uplo2, n, &c_b14, &a[a_offset], lda, &y[j * y_dim1 + 1], &c__1, &c_b15, &res[1], &c__1, prec_type__);
            }
            else
            {
                blas_csymv2_x_(&uplo2, n, &c_b14, &a[a_offset], lda, &y[j * y_dim1 + 1], &y_tail__[1], &c__1, &c_b15, &res[1], & c__1, prec_type__);
            }
            /* XXX: RES is no longer needed. */
            ccopy_(n, &res[1], &c__1, &dy[1], &c__1);
            csytrs_(uplo, n, &c__1, &af[af_offset], ldaf, &ipiv[1], &dy[1], n, info);
            /* Calculate relative changes DX_X, DZ_Z and ratios DXRAT, DZRAT. */
            normx = 0.f;
            normy = 0.f;
            normdx = 0.f;
            dz_z__ = 0.f;
            ymin = hugeval;
            i__3 = *n;
            for (i__ = 1;
                    i__ <= i__3;
                    ++i__)
            {
                i__4 = i__ + j * y_dim1;
                yk = (r__1 = y[i__4].r, f2c_abs(r__1)) + (r__2 = r_imag(&y[i__ + j * y_dim1]), f2c_abs(r__2));
                i__4 = i__;
                dyk = (r__1 = dy[i__4].r, f2c_abs(r__1)) + (r__2 = r_imag(&dy[i__] ), f2c_abs(r__2));
                if (yk != 0.f)
                {
                    /* Computing MAX */
                    r__1 = dz_z__;
                    r__2 = dyk / yk; // , expr subst
                    dz_z__ = max(r__1,r__2);
                }
                else if (dyk != 0.f)
                {
                    dz_z__ = hugeval;
                }
                ymin = min(ymin,yk);
                normy = max(normy,yk);
                if (*colequ)
                {
                    /* Computing MAX */
                    r__1 = normx;
                    r__2 = yk * c__[i__]; // , expr subst
                    normx = max(r__1,r__2);
                    /* Computing MAX */
                    r__1 = normdx;
                    r__2 = dyk * c__[i__]; // , expr subst
                    normdx = max(r__1,r__2);
                }
                else
                {
                    normx = normy;
                    normdx = max(normdx,dyk);
                }
            }
            if (normx != 0.f)
            {
                dx_x__ = normdx / normx;
            }
            else if (normdx == 0.f)
            {
                dx_x__ = 0.f;
            }
            else
            {
                dx_x__ = hugeval;
            }
            dxrat = normdx / prevnormdx;
            dzrat = dz_z__ / prev_dz_z__;
            /* Check termination criteria. */
            if (ymin * *rcond < incr_thresh__ * normy && y_prec_state__ < 2)
            {
                incr_prec__ = TRUE_;
            }
            if (x_state__ == 3 && dxrat <= *rthresh)
            {
                x_state__ = 1;
            }
            if (x_state__ == 1)
            {
                if (dx_x__ <= eps)
                {
                    x_state__ = 2;
                }
                else if (dxrat > *rthresh)
                {
                    if (y_prec_state__ != 2)
                    {
                        incr_prec__ = TRUE_;
                    }
                    else
                    {
                        x_state__ = 3;
                    }
                }
                else
                {
                    if (dxrat > dxratmax)
                    {
                        dxratmax = dxrat;
                    }
                }
                if (x_state__ > 1)
                {
                    final_dx_x__ = dx_x__;
                }
            }
            if (z_state__ == 0 && dz_z__ <= *dz_ub__)
            {
                z_state__ = 1;
            }
            if (z_state__ == 3 && dzrat <= *rthresh)
            {
                z_state__ = 1;
            }
            if (z_state__ == 1)
            {
                if (dz_z__ <= eps)
                {
                    z_state__ = 2;
                }
                else if (dz_z__ > *dz_ub__)
                {
                    z_state__ = 0;
                    dzratmax = 0.f;
                    final_dz_z__ = hugeval;
                }
                else if (dzrat > *rthresh)
                {
                    if (y_prec_state__ != 2)
                    {
                        incr_prec__ = TRUE_;
                    }
                    else
                    {
                        z_state__ = 3;
                    }
                }
                else
                {
                    if (dzrat > dzratmax)
                    {
                        dzratmax = dzrat;
                    }
                }
                if (z_state__ > 1)
                {
                    final_dz_z__ = dz_z__;
                }
            }
            if (x_state__ != 1 && (*ignore_cwise__ || z_state__ != 1))
            {
                goto L666;
            }
            if (incr_prec__)
            {
                incr_prec__ = FALSE_;
                ++y_prec_state__;
                i__3 = *n;
                for (i__ = 1;
                        i__ <= i__3;
                        ++i__)
                {
                    i__4 = i__;
                    y_tail__[i__4].r = 0.f;
                    y_tail__[i__4].i = 0.f; // , expr subst
                }
            }
            prevnormdx = normdx;
            prev_dz_z__ = dz_z__;
            /* Update soluton. */
            if (y_prec_state__ < 2)
            {
                caxpy_(n, &c_b15, &dy[1], &c__1, &y[j * y_dim1 + 1], &c__1);
            }
            else
            {
                cla_wwaddw_(n, &y[j * y_dim1 + 1], &y_tail__[1], &dy[1]);
            }
        }
        /* Target of "IF (Z_STOP .AND. X_STOP)". Sun's f77 won't CALL F90_EXIT. */
L666: /* Set final_* when cnt hits ithresh. */
        if (x_state__ == 1)
        {
            final_dx_x__ = dx_x__;
        }
        if (z_state__ == 1)
        {
            final_dz_z__ = dz_z__;
        }
        /* Compute error bounds. */
        if (*n_norms__ >= 1)
        {
            err_bnds_norm__[j + (err_bnds_norm_dim1 << 1)] = final_dx_x__ / ( 1 - dxratmax);
        }
        if (*n_norms__ >= 2)
        {
            err_bnds_comp__[j + (err_bnds_comp_dim1 << 1)] = final_dz_z__ / ( 1 - dzratmax);
        }
        /* Compute componentwise relative backward error from formula */
        /* max(i) ( f2c_abs(R(i)) / ( f2c_abs(op(A_s))*f2c_abs(Y) + f2c_abs(B_s) )(i) ) */
        /* where f2c_abs(Z) is the componentwise absolute value of the matrix */
        /* or vector Z. */
        /* Compute residual RES = B_s - op(A_s) * Y, */
        /* op(A) = A, A**T, or A**H depending on TRANS (and type). */
        ccopy_(n, &b[j * b_dim1 + 1], &c__1, &res[1], &c__1);
        csymv_(uplo, n, &c_b14, &a[a_offset], lda, &y[j * y_dim1 + 1], &c__1, &c_b15, &res[1], &c__1);
        i__2 = *n;
        for (i__ = 1;
                i__ <= i__2;
                ++i__)
        {
            i__3 = i__ + j * b_dim1;
            ayb[i__] = (r__1 = b[i__3].r, f2c_abs(r__1)) + (r__2 = r_imag(&b[i__ + j * b_dim1]), f2c_abs(r__2));
        }
        /* Compute f2c_abs(op(A_s))*f2c_abs(Y) + f2c_abs(B_s). */
        cla_syamv_(&uplo2, n, &c_b37, &a[a_offset], lda, &y[j * y_dim1 + 1], &c__1, &c_b37, &ayb[1], &c__1);
        cla_lin_berr_(n, n, &c__1, &res[1], &ayb[1], &berr_out__[j]);
        /* End of loop for each RHS. */
    }
    return 0;
}
Пример #3
0
/* Subroutine */ int csysvx_(char *fact, char *uplo, integer *n, integer *
	nrhs, complex *a, integer *lda, complex *af, integer *ldaf, integer *
	ipiv, complex *b, integer *ldb, complex *x, integer *ldx, real *rcond, 
	 real *ferr, real *berr, complex *work, integer *lwork, real *rwork, 
	integer *info)
{
    /* System generated locals */
    integer a_dim1, a_offset, af_dim1, af_offset, b_dim1, b_offset, x_dim1, 
	    x_offset, i__1, i__2;

    /* Local variables */
    integer nb;
    extern logical lsame_(char *, char *);
    real anorm;
    extern doublereal slamch_(char *);
    logical nofact;
    extern /* Subroutine */ int clacpy_(char *, integer *, integer *, complex 
	    *, integer *, complex *, integer *), xerbla_(char *, 
	    integer *);
    extern integer ilaenv_(integer *, char *, char *, integer *, integer *, 
	    integer *, integer *);
    extern doublereal clansy_(char *, char *, integer *, complex *, integer *, 
	     real *);
    extern /* Subroutine */ int csycon_(char *, integer *, complex *, integer 
	    *, integer *, real *, real *, complex *, integer *), 
	    csyrfs_(char *, integer *, integer *, complex *, integer *, 
	    complex *, integer *, integer *, complex *, integer *, complex *, 
	    integer *, real *, real *, complex *, real *, integer *), 
	    csytrf_(char *, integer *, complex *, integer *, integer *, 
	    complex *, integer *, integer *);
    integer lwkopt;
    logical lquery;
    extern /* Subroutine */ int csytrs_(char *, integer *, integer *, complex 
	    *, integer *, integer *, complex *, integer *, integer *);


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

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

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

/*  CSYSVX uses the diagonal pivoting factorization to compute the */
/*  solution to a complex system of linear equations A * X = B, */
/*  where A is an N-by-N symmetric 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 = 'N', the diagonal pivoting method is used to factor A. */
/*     The form of the factorization is */
/*        A = U * D * U**T,  if UPLO = 'U', or */
/*        A = L * D * L**T,  if UPLO = 'L', */
/*     where U (or L) is a product of permutation and unit upper (lower) */
/*     triangular matrices, and D is symmetric and block diagonal with */
/*     1-by-1 and 2-by-2 diagonal blocks. */

/*  2. If some D(i,i)=0, so that D is exactly singular, 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. */

/*  3. The system of equations is solved for X using the factored form */
/*     of A. */

/*  4. Iterative refinement is applied to improve the computed solution */
/*     matrix and calculate error bounds and backward error estimates */
/*     for it. */

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

/*  FACT    (input) CHARACTER*1 */
/*          Specifies whether or not the factored form of A has been */
/*          supplied on entry. */
/*          = 'F':  On entry, AF and IPIV contain the factored form */
/*                  of A.  A, AF and IPIV will not be modified. */
/*          = 'N':  The matrix A will be copied to AF 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. */

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

/*  A       (input) COMPLEX array, dimension (LDA,N) */
/*          The symmetric matrix A.  If UPLO = 'U', the leading N-by-N */
/*          upper triangular part of A contains the upper triangular part */
/*          of the matrix A, and the strictly lower triangular part of A */
/*          is not referenced.  If UPLO = 'L', the leading N-by-N lower */
/*          triangular part of A contains the lower triangular part of */
/*          the matrix A, and the strictly upper triangular part of A is */
/*          not referenced. */

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

/*  AF      (input or output) COMPLEX array, dimension (LDAF,N) */
/*          If FACT = 'F', then AF is an input argument and on entry */
/*          contains the block diagonal matrix D and the multipliers used */
/*          to obtain the factor U or L from the factorization */
/*          A = U*D*U**T or A = L*D*L**T as computed by CSYTRF. */

/*          If FACT = 'N', then AF is an output argument and on exit */
/*          returns the block diagonal matrix D and the multipliers used */
/*          to obtain the factor U or L from the factorization */
/*          A = U*D*U**T or A = L*D*L**T. */

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

/*  IPIV    (input or output) INTEGER array, dimension (N) */
/*          If FACT = 'F', then IPIV is an input argument and on entry */
/*          contains details of the interchanges and the block structure */
/*          of D, as determined by CSYTRF. */
/*          If IPIV(k) > 0, then rows and columns k and IPIV(k) were */
/*          interchanged and D(k,k) is a 1-by-1 diagonal block. */
/*          If UPLO = 'U' and IPIV(k) = IPIV(k-1) < 0, then rows and */
/*          columns k-1 and -IPIV(k) were interchanged and D(k-1:k,k-1:k) */
/*          is a 2-by-2 diagonal block.  If UPLO = 'L' and IPIV(k) = */
/*          IPIV(k+1) < 0, then rows and columns k+1 and -IPIV(k) were */
/*          interchanged and D(k:k+1,k:k+1) is a 2-by-2 diagonal block. */

/*          If FACT = 'N', then IPIV is an output argument and on exit */
/*          contains details of the interchanges and the block structure */
/*          of D, as determined by CSYTRF. */

/*  B       (input) COMPLEX array, dimension (LDB,NRHS) */
/*          The N-by-NRHS right hand side matrix 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. */

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

/*  LWORK   (input) INTEGER */
/*          The length of WORK.  LWORK >= max(1,2*N), and for best */
/*          performance, when FACT = 'N', LWORK >= max(1,2*N,N*NB), where */
/*          NB is the optimal blocksize for CSYTRF. */

/*          If LWORK = -1, then a workspace query is assumed; the routine */
/*          only calculates the optimal size of the WORK array, returns */
/*          this value as the first entry of the WORK array, and no error */
/*          message related to LWORK is issued by XERBLA. */

/*  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:  D(i,i) is exactly zero.  The factorization */
/*                       has been completed but the factor D is exactly */
/*                       singular, so the solution and error bounds could */
/*                       not be computed. RCOND = 0 is returned. */
/*                = N+1: D 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. */

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

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

/*     Test the input parameters. */

    /* Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    af_dim1 = *ldaf;
    af_offset = 1 + af_dim1;
    af -= af_offset;
    --ipiv;
    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");
    lquery = *lwork == -1;
    if (! nofact && ! lsame_(fact, "F")) {
	*info = -1;
    } else if (! lsame_(uplo, "U") && ! lsame_(uplo, 
	    "L")) {
	*info = -2;
    } else if (*n < 0) {
	*info = -3;
    } else if (*nrhs < 0) {
	*info = -4;
    } else if (*lda < max(1,*n)) {
	*info = -6;
    } else if (*ldaf < max(1,*n)) {
	*info = -8;
    } else if (*ldb < max(1,*n)) {
	*info = -11;
    } else if (*ldx < max(1,*n)) {
	*info = -13;
    } else /* if(complicated condition) */ {
/* Computing MAX */
	i__1 = 1, i__2 = *n << 1;
	if (*lwork < max(i__1,i__2) && ! lquery) {
	    *info = -18;
	}
    }

    if (*info == 0) {
/* Computing MAX */
	i__1 = 1, i__2 = *n << 1;
	lwkopt = max(i__1,i__2);
	if (nofact) {
	    nb = ilaenv_(&c__1, "CSYTRF", uplo, n, &c_n1, &c_n1, &c_n1);
/* Computing MAX */
	    i__1 = lwkopt, i__2 = *n * nb;
	    lwkopt = max(i__1,i__2);
	}
	work[1].r = (real) lwkopt, work[1].i = 0.f;
    }

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

    if (nofact) {

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

	clacpy_(uplo, n, n, &a[a_offset], lda, &af[af_offset], ldaf);
	csytrf_(uplo, n, &af[af_offset], ldaf, &ipiv[1], &work[1], lwork, 
		info);

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

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

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

    anorm = clansy_("I", uplo, n, &a[a_offset], lda, &rwork[1]);

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

    csycon_(uplo, n, &af[af_offset], ldaf, &ipiv[1], &anorm, rcond, &work[1], 
	    info);

/*     Compute the solution vectors X. */

    clacpy_("Full", n, nrhs, &b[b_offset], ldb, &x[x_offset], ldx);
    csytrs_(uplo, n, nrhs, &af[af_offset], ldaf, &ipiv[1], &x[x_offset], ldx, 
	    info);

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

    csyrfs_(uplo, n, nrhs, &a[a_offset], lda, &af[af_offset], ldaf, &ipiv[1], 
	    &b[b_offset], ldb, &x[x_offset], ldx, &ferr[1], &berr[1], &work[1]
, &rwork[1], info);

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

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

    work[1].r = (real) lwkopt, work[1].i = 0.f;

    return 0;

/*     End of CSYSVX */

} /* csysvx_ */
Пример #4
0
/* Subroutine */
int csysv_(char *uplo, integer *n, integer *nrhs, complex *a, integer *lda, integer *ipiv, complex *b, integer *ldb, complex *work, integer *lwork, integer *info)
{
    /* System generated locals */
    integer a_dim1, a_offset, b_dim1, b_offset, i__1;
    /* Local variables */
    extern logical lsame_(char *, char *);
    extern /* Subroutine */
    int xerbla_(char *, integer *), csytrf_( char *, integer *, complex *, integer *, integer *, complex *, integer *, integer *);
    integer lwkopt;
    logical lquery;
    extern /* Subroutine */
    int csytrs_(char *, integer *, integer *, complex *, integer *, integer *, complex *, integer *, integer *), csytrs2_(char *, integer *, integer *, complex *, integer *, integer *, complex *, integer *, complex *, integer *);
    /* -- LAPACK driver routine (version 3.4.0) -- */
    /* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
    /* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
    /* November 2011 */
    /* .. Scalar Arguments .. */
    /* .. */
    /* .. Array Arguments .. */
    /* .. */
    /* ===================================================================== */
    /* .. Local Scalars .. */
    /* .. */
    /* .. External Functions .. */
    /* .. */
    /* .. External Subroutines .. */
    /* .. */
    /* .. Intrinsic Functions .. */
    /* .. */
    /* .. Executable Statements .. */
    /* Test the input parameters. */
    /* Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    --ipiv;
    b_dim1 = *ldb;
    b_offset = 1 + b_dim1;
    b -= b_offset;
    --work;
    /* Function Body */
    *info = 0;
    lquery = *lwork == -1;
    if (! lsame_(uplo, "U") && ! lsame_(uplo, "L"))
    {
        *info = -1;
    }
    else if (*n < 0)
    {
        *info = -2;
    }
    else if (*nrhs < 0)
    {
        *info = -3;
    }
    else if (*lda < max(1,*n))
    {
        *info = -5;
    }
    else if (*ldb < max(1,*n))
    {
        *info = -8;
    }
    else if (*lwork < 1 && ! lquery)
    {
        *info = -10;
    }
    if (*info == 0)
    {
        if (*n == 0)
        {
            lwkopt = 1;
        }
        else
        {
            csytrf_(uplo, n, &a[a_offset], lda, &ipiv[1], &work[1], &c_n1, info);
            lwkopt = work[1].r;
        }
        work[1].r = (real) lwkopt;
        work[1].i = 0.f; // , expr subst
    }
    if (*info != 0)
    {
        i__1 = -(*info);
        xerbla_("CSYSV ", &i__1);
        return 0;
    }
    else if (lquery)
    {
        return 0;
    }
    /* Compute the factorization A = U*D*U**T or A = L*D*L**T. */
    csytrf_(uplo, n, &a[a_offset], lda, &ipiv[1], &work[1], lwork, info);
    if (*info == 0)
    {
        /* Solve the system A*X = B, overwriting B with X. */
        if (*lwork < *n)
        {
            /* Solve with TRS ( Use Level BLAS 2) */
            csytrs_(uplo, n, nrhs, &a[a_offset], lda, &ipiv[1], &b[b_offset], ldb, info);
        }
        else
        {
            /* Solve with TRS2 ( Use Level BLAS 3) */
            csytrs2_(uplo, n, nrhs, &a[a_offset], lda, &ipiv[1], &b[b_offset], ldb, &work[1], info);
        }
    }
    work[1].r = (real) lwkopt;
    work[1].i = 0.f; // , expr subst
    return 0;
    /* End of CSYSV */
}
Пример #5
0
/* ===================================================================== */
real cla_syrcond_c_(char *uplo, integer *n, complex *a, integer *lda, complex *af, integer *ldaf, integer *ipiv, real *c__, logical *capply, integer *info, complex *work, real *rwork)
{
    /* System generated locals */
    integer a_dim1, a_offset, af_dim1, af_offset, i__1, i__2, i__3, i__4;
    real ret_val, r__1, r__2;
    complex q__1;
    /* Builtin functions */
    double r_imag(complex *);
    /* Local variables */
    integer i__, j;
    logical up;
    real tmp;
    integer kase;
    extern logical lsame_(char *, char *);
    integer isave[3];
    real anorm;
    logical upper;
    extern /* Subroutine */
    int clacn2_(integer *, complex *, complex *, real *, integer *, integer *), xerbla_(char *, integer *);
    real ainvnm;
    extern /* Subroutine */
    int csytrs_(char *, integer *, integer *, complex *, integer *, integer *, complex *, integer *, integer *);
    /* -- LAPACK computational routine (version 3.4.2) -- */
    /* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
    /* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
    /* September 2012 */
    /* .. Scalar Arguments .. */
    /* .. */
    /* .. Array Arguments .. */
    /* .. */
    /* ===================================================================== */
    /* .. Local Scalars .. */
    /* .. */
    /* .. Local Arrays .. */
    /* .. */
    /* .. External Functions .. */
    /* .. */
    /* .. External Subroutines .. */
    /* .. */
    /* .. Intrinsic Functions .. */
    /* .. */
    /* .. Statement Functions .. */
    /* .. */
    /* .. Statement Function Definitions .. */
    /* .. */
    /* .. Executable Statements .. */
    /* Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    af_dim1 = *ldaf;
    af_offset = 1 + af_dim1;
    af -= af_offset;
    --ipiv;
    --c__;
    --work;
    --rwork;
    /* Function Body */
    ret_val = 0.f;
    *info = 0;
    upper = lsame_(uplo, "U");
    if (! upper && ! lsame_(uplo, "L"))
    {
        *info = -1;
    }
    else if (*n < 0)
    {
        *info = -2;
    }
    else if (*lda < max(1,*n))
    {
        *info = -4;
    }
    else if (*ldaf < max(1,*n))
    {
        *info = -6;
    }
    if (*info != 0)
    {
        i__1 = -(*info);
        xerbla_("CLA_SYRCOND_C", &i__1);
        return ret_val;
    }
    up = FALSE_;
    if (lsame_(uplo, "U"))
    {
        up = TRUE_;
    }
    /* Compute norm of op(A)*op2(C). */
    anorm = 0.f;
    if (up)
    {
        i__1 = *n;
        for (i__ = 1;
                i__ <= i__1;
                ++i__)
        {
            tmp = 0.f;
            if (*capply)
            {
                i__2 = i__;
                for (j = 1;
                        j <= i__2;
                        ++j)
                {
                    i__3 = j + i__ * a_dim1;
                    tmp += ((r__1 = a[i__3].r, abs(r__1)) + (r__2 = r_imag(&a[ j + i__ * a_dim1]), abs(r__2))) / c__[j];
                }
                i__2 = *n;
                for (j = i__ + 1;
                        j <= i__2;
                        ++j)
                {
                    i__3 = i__ + j * a_dim1;
                    tmp += ((r__1 = a[i__3].r, abs(r__1)) + (r__2 = r_imag(&a[ i__ + j * a_dim1]), abs(r__2))) / c__[j];
                }
            }
            else
            {
                i__2 = i__;
                for (j = 1;
                        j <= i__2;
                        ++j)
                {
                    i__3 = j + i__ * a_dim1;
                    tmp += (r__1 = a[i__3].r, abs(r__1)) + (r__2 = r_imag(&a[ j + i__ * a_dim1]), abs(r__2));
                }
                i__2 = *n;
                for (j = i__ + 1;
                        j <= i__2;
                        ++j)
                {
                    i__3 = i__ + j * a_dim1;
                    tmp += (r__1 = a[i__3].r, abs(r__1)) + (r__2 = r_imag(&a[ i__ + j * a_dim1]), abs(r__2));
                }
            }
            rwork[i__] = tmp;
            anorm = max(anorm,tmp);
        }
    }
    else
    {
        i__1 = *n;
        for (i__ = 1;
                i__ <= i__1;
                ++i__)
        {
            tmp = 0.f;
            if (*capply)
            {
                i__2 = i__;
                for (j = 1;
                        j <= i__2;
                        ++j)
                {
                    i__3 = i__ + j * a_dim1;
                    tmp += ((r__1 = a[i__3].r, abs(r__1)) + (r__2 = r_imag(&a[ i__ + j * a_dim1]), abs(r__2))) / c__[j];
                }
                i__2 = *n;
                for (j = i__ + 1;
                        j <= i__2;
                        ++j)
                {
                    i__3 = j + i__ * a_dim1;
                    tmp += ((r__1 = a[i__3].r, abs(r__1)) + (r__2 = r_imag(&a[ j + i__ * a_dim1]), abs(r__2))) / c__[j];
                }
            }
            else
            {
                i__2 = i__;
                for (j = 1;
                        j <= i__2;
                        ++j)
                {
                    i__3 = i__ + j * a_dim1;
                    tmp += (r__1 = a[i__3].r, abs(r__1)) + (r__2 = r_imag(&a[ i__ + j * a_dim1]), abs(r__2));
                }
                i__2 = *n;
                for (j = i__ + 1;
                        j <= i__2;
                        ++j)
                {
                    i__3 = j + i__ * a_dim1;
                    tmp += (r__1 = a[i__3].r, abs(r__1)) + (r__2 = r_imag(&a[ j + i__ * a_dim1]), abs(r__2));
                }
            }
            rwork[i__] = tmp;
            anorm = max(anorm,tmp);
        }
    }
    /* Quick return if possible. */
    if (*n == 0)
    {
        ret_val = 1.f;
        return ret_val;
    }
    else if (anorm == 0.f)
    {
        return ret_val;
    }
    /* Estimate the norm of inv(op(A)). */
    ainvnm = 0.f;
    kase = 0;
L10:
    clacn2_(n, &work[*n + 1], &work[1], &ainvnm, &kase, isave);
    if (kase != 0)
    {
        if (kase == 2)
        {
            /* Multiply by R. */
            i__1 = *n;
            for (i__ = 1;
                    i__ <= i__1;
                    ++i__)
            {
                i__2 = i__;
                i__3 = i__;
                i__4 = i__;
                q__1.r = rwork[i__4] * work[i__3].r;
                q__1.i = rwork[i__4] * work[i__3].i; // , expr subst
                work[i__2].r = q__1.r;
                work[i__2].i = q__1.i; // , expr subst
            }
            if (up)
            {
                csytrs_("U", n, &c__1, &af[af_offset], ldaf, &ipiv[1], &work[ 1], n, info);
            }
            else
            {
                csytrs_("L", n, &c__1, &af[af_offset], ldaf, &ipiv[1], &work[ 1], n, info);
            }
            /* Multiply by inv(C). */
            if (*capply)
            {
                i__1 = *n;
                for (i__ = 1;
                        i__ <= i__1;
                        ++i__)
                {
                    i__2 = i__;
                    i__3 = i__;
                    i__4 = i__;
                    q__1.r = c__[i__4] * work[i__3].r;
                    q__1.i = c__[i__4] * work[i__3].i; // , expr subst
                    work[i__2].r = q__1.r;
                    work[i__2].i = q__1.i; // , expr subst
                }
            }
        }
        else
        {
            /* Multiply by inv(C**T). */
            if (*capply)
            {
                i__1 = *n;
                for (i__ = 1;
                        i__ <= i__1;
                        ++i__)
                {
                    i__2 = i__;
                    i__3 = i__;
                    i__4 = i__;
                    q__1.r = c__[i__4] * work[i__3].r;
                    q__1.i = c__[i__4] * work[i__3].i; // , expr subst
                    work[i__2].r = q__1.r;
                    work[i__2].i = q__1.i; // , expr subst
                }
            }
            if (up)
            {
                csytrs_("U", n, &c__1, &af[af_offset], ldaf, &ipiv[1], &work[ 1], n, info);
            }
            else
            {
                csytrs_("L", n, &c__1, &af[af_offset], ldaf, &ipiv[1], &work[ 1], n, info);
            }
            /* Multiply by R. */
            i__1 = *n;
            for (i__ = 1;
                    i__ <= i__1;
                    ++i__)
            {
                i__2 = i__;
                i__3 = i__;
                i__4 = i__;
                q__1.r = rwork[i__4] * work[i__3].r;
                q__1.i = rwork[i__4] * work[i__3].i; // , expr subst
                work[i__2].r = q__1.r;
                work[i__2].i = q__1.i; // , expr subst
            }
        }
        goto L10;
    }
    /* Compute the estimate of the reciprocal condition number. */
    if (ainvnm != 0.f)
    {
        ret_val = 1.f / ainvnm;
    }
    return ret_val;
}
Пример #6
0
/* Subroutine */
int csysvx_(char *fact, char *uplo, integer *n, integer * nrhs, complex *a, integer *lda, complex *af, integer *ldaf, integer * ipiv, complex *b, integer *ldb, complex *x, integer *ldx, real *rcond, real *ferr, real *berr, complex *work, integer *lwork, real *rwork, integer *info)
{
    /* System generated locals */
    integer a_dim1, a_offset, af_dim1, af_offset, b_dim1, b_offset, x_dim1, x_offset, i__1, i__2;
    /* Local variables */
    integer nb;
    extern logical lsame_(char *, char *);
    real anorm;
    extern real slamch_(char *);
    logical nofact;
    extern /* Subroutine */
    int clacpy_(char *, integer *, integer *, complex *, integer *, complex *, integer *), xerbla_(char *, integer *);
    extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *);
    extern real clansy_(char *, char *, integer *, complex *, integer *, real *);
    extern /* Subroutine */
    int csycon_(char *, integer *, complex *, integer *, integer *, real *, real *, complex *, integer *), csyrfs_(char *, integer *, integer *, complex *, integer *, complex *, integer *, integer *, complex *, integer *, complex *, integer *, real *, real *, complex *, real *, integer *), csytrf_(char *, integer *, complex *, integer *, integer *, complex *, integer *, integer *);
    integer lwkopt;
    logical lquery;
    extern /* Subroutine */
    int csytrs_(char *, integer *, integer *, complex *, integer *, integer *, complex *, integer *, integer *);
    /* -- 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 .. */
    /* Test the input parameters. */
    /* Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    af_dim1 = *ldaf;
    af_offset = 1 + af_dim1;
    af -= af_offset;
    --ipiv;
    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");
    lquery = *lwork == -1;
    if (! nofact && ! lsame_(fact, "F"))
    {
        *info = -1;
    }
    else if (! lsame_(uplo, "U") && ! lsame_(uplo, "L"))
    {
        *info = -2;
    }
    else if (*n < 0)
    {
        *info = -3;
    }
    else if (*nrhs < 0)
    {
        *info = -4;
    }
    else if (*lda < max(1,*n))
    {
        *info = -6;
    }
    else if (*ldaf < max(1,*n))
    {
        *info = -8;
    }
    else if (*ldb < max(1,*n))
    {
        *info = -11;
    }
    else if (*ldx < max(1,*n))
    {
        *info = -13;
    }
    else /* if(complicated condition) */
    {
        /* Computing MAX */
        i__1 = 1;
        i__2 = *n << 1; // , expr subst
        if (*lwork < max(i__1,i__2) && ! lquery)
        {
            *info = -18;
        }
    }
    if (*info == 0)
    {
        /* Computing MAX */
        i__1 = 1;
        i__2 = *n << 1; // , expr subst
        lwkopt = max(i__1,i__2);
        if (nofact)
        {
            nb = ilaenv_(&c__1, "CSYTRF", uplo, n, &c_n1, &c_n1, &c_n1);
            /* Computing MAX */
            i__1 = lwkopt;
            i__2 = *n * nb; // , expr subst
            lwkopt = max(i__1,i__2);
        }
        work[1].r = (real) lwkopt;
        work[1].i = 0.f; // , expr subst
    }
    if (*info != 0)
    {
        i__1 = -(*info);
        xerbla_("CSYSVX", &i__1);
        return 0;
    }
    else if (lquery)
    {
        return 0;
    }
    if (nofact)
    {
        /* Compute the factorization A = U*D*U**T or A = L*D*L**T. */
        clacpy_(uplo, n, n, &a[a_offset], lda, &af[af_offset], ldaf);
        csytrf_(uplo, n, &af[af_offset], ldaf, &ipiv[1], &work[1], lwork, info);
        /* Return if INFO is non-zero. */
        if (*info > 0)
        {
            *rcond = 0.f;
            return 0;
        }
    }
    /* Compute the norm of the matrix A. */
    anorm = clansy_("I", uplo, n, &a[a_offset], lda, &rwork[1]);
    /* Compute the reciprocal of the condition number of A. */
    csycon_(uplo, n, &af[af_offset], ldaf, &ipiv[1], &anorm, rcond, &work[1], info);
    /* Compute the solution vectors X. */
    clacpy_("Full", n, nrhs, &b[b_offset], ldb, &x[x_offset], ldx);
    csytrs_(uplo, n, nrhs, &af[af_offset], ldaf, &ipiv[1], &x[x_offset], ldx, info);
    /* Use iterative refinement to improve the computed solutions and */
    /* compute error bounds and backward error estimates for them. */
    csyrfs_(uplo, n, nrhs, &a[a_offset], lda, &af[af_offset], ldaf, &ipiv[1], &b[b_offset], ldb, &x[x_offset], ldx, &ferr[1], &berr[1], &work[1] , &rwork[1], info);
    /* Set INFO = N+1 if the matrix is singular to working precision. */
    if (*rcond < slamch_("Epsilon"))
    {
        *info = *n + 1;
    }
    work[1].r = (real) lwkopt;
    work[1].i = 0.f; // , expr subst
    return 0;
    /* End of CSYSVX */
}
Пример #7
0
 int csycon_(char *uplo, int *n, complex *a, int *lda, 
	 int *ipiv, float *anorm, float *rcond, complex *work, int *
	info)
{
    /* System generated locals */
    int a_dim1, a_offset, i__1, i__2;

    /* Local variables */
    int i__, kase;
    extern int lsame_(char *, char *);
    int isave[3];
    int upper;
    extern  int clacn2_(int *, complex *, complex *, float 
	    *, int *, int *), xerbla_(char *, int *);
    float ainvnm;
    extern  int csytrs_(char *, int *, int *, complex 
	    *, int *, int *, complex *, int *, int *);


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

/*     Modified to call CLACN2 in place of CLACON, 10 Feb 03, SJH. */

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

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

/*  CSYCON estimates the reciprocal of the condition number (in the */
/*  1-norm) of a complex symmetric matrix A using the factorization */
/*  A = U*D*U**T or A = L*D*L**T computed by CSYTRF. */

/*  An estimate is obtained for norm(inv(A)), and the reciprocal of the */
/*  condition number is computed as RCOND = 1 / (ANORM * norm(inv(A))). */

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

/*  UPLO    (input) CHARACTER*1 */
/*          Specifies whether the details of the factorization are stored */
/*          as an upper or lower triangular matrix. */
/*          = 'U':  Upper triangular, form is A = U*D*U**T; */
/*          = 'L':  Lower triangular, form is A = L*D*L**T. */

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

/*  A       (input) COMPLEX array, dimension (LDA,N) */
/*          The block diagonal matrix D and the multipliers used to */
/*          obtain the factor U or L as computed by CSYTRF. */

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

/*  IPIV    (input) INTEGER array, dimension (N) */
/*          Details of the interchanges and the block structure of D */
/*          as determined by CSYTRF. */

/*  ANORM   (input) REAL */
/*          The 1-norm of the original matrix A. */

/*  RCOND   (output) REAL */
/*          The reciprocal of the condition number of the matrix A, */
/*          computed as RCOND = 1/(ANORM * AINVNM), where AINVNM is an */
/*          estimate of the 1-norm of inv(A) computed in this routine. */

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

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

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

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

/*     Test the input parameters. */

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

    /* Function Body */
    *info = 0;
    upper = lsame_(uplo, "U");
    if (! upper && ! lsame_(uplo, "L")) {
	*info = -1;
    } else if (*n < 0) {
	*info = -2;
    } else if (*lda < MAX(1,*n)) {
	*info = -4;
    } else if (*anorm < 0.f) {
	*info = -6;
    }
    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("CSYCON", &i__1);
	return 0;
    }

/*     Quick return if possible */

    *rcond = 0.f;
    if (*n == 0) {
	*rcond = 1.f;
	return 0;
    } else if (*anorm <= 0.f) {
	return 0;
    }

/*     Check that the diagonal matrix D is nonsingular. */

    if (upper) {

/*        Upper triangular storage: examine D from bottom to top */

	for (i__ = *n; i__ >= 1; --i__) {
	    i__1 = i__ + i__ * a_dim1;
	    if (ipiv[i__] > 0 && (a[i__1].r == 0.f && a[i__1].i == 0.f)) {
		return 0;
	    }
/* L10: */
	}
    } else {

/*        Lower triangular storage: examine D from top to bottom. */

	i__1 = *n;
	for (i__ = 1; i__ <= i__1; ++i__) {
	    i__2 = i__ + i__ * a_dim1;
	    if (ipiv[i__] > 0 && (a[i__2].r == 0.f && a[i__2].i == 0.f)) {
		return 0;
	    }
/* L20: */
	}
    }

/*     Estimate the 1-norm of the inverse. */

    kase = 0;
L30:
    clacn2_(n, &work[*n + 1], &work[1], &ainvnm, &kase, isave);
    if (kase != 0) {

/*        Multiply by inv(L*D*L') or inv(U*D*U'). */

	csytrs_(uplo, n, &c__1, &a[a_offset], lda, &ipiv[1], &work[1], n, 
		info);
	goto L30;
    }

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

    if (ainvnm != 0.f) {
	*rcond = 1.f / ainvnm / *anorm;
    }

    return 0;

/*     End of CSYCON */

} /* csycon_ */
Пример #8
0
/* Subroutine */ int csycon_(char *uplo, integer *n, complex *a, integer *lda,
	 integer *ipiv, real *anorm, real *rcond, complex *work, integer *
	info)
{
/*  -- LAPACK routine (version 3.0) --   
       Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,   
       Courant Institute, Argonne National Lab, and Rice University   
       March 31, 1993   


    Purpose   
    =======   

    CSYCON estimates the reciprocal of the condition number (in the   
    1-norm) of a complex symmetric matrix A using the factorization   
    A = U*D*U**T or A = L*D*L**T computed by CSYTRF.   

    An estimate is obtained for norm(inv(A)), and the reciprocal of the   
    condition number is computed as RCOND = 1 / (ANORM * norm(inv(A))).   

    Arguments   
    =========   

    UPLO    (input) CHARACTER*1   
            Specifies whether the details of the factorization are stored   
            as an upper or lower triangular matrix.   
            = 'U':  Upper triangular, form is A = U*D*U**T;   
            = 'L':  Lower triangular, form is A = L*D*L**T.   

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

    A       (input) COMPLEX array, dimension (LDA,N)   
            The block diagonal matrix D and the multipliers used to   
            obtain the factor U or L as computed by CSYTRF.   

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

    IPIV    (input) INTEGER array, dimension (N)   
            Details of the interchanges and the block structure of D   
            as determined by CSYTRF.   

    ANORM   (input) REAL   
            The 1-norm of the original matrix A.   

    RCOND   (output) REAL   
            The reciprocal of the condition number of the matrix A,   
            computed as RCOND = 1/(ANORM * AINVNM), where AINVNM is an   
            estimate of the 1-norm of inv(A) computed in this routine.   

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

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

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


       Test the input parameters.   

       Parameter adjustments */
    /* Table of constant values */
    static integer c__1 = 1;
    
    /* System generated locals */
    integer a_dim1, a_offset, i__1, i__2;
    /* Local variables */
    static integer kase, i__;
    extern logical lsame_(char *, char *);
    static logical upper;
    extern /* Subroutine */ int clacon_(integer *, complex *, complex *, real 
	    *, integer *), xerbla_(char *, integer *);
    static real ainvnm;
    extern /* Subroutine */ int csytrs_(char *, integer *, integer *, complex 
	    *, integer *, integer *, complex *, integer *, integer *);
#define a_subscr(a_1,a_2) (a_2)*a_dim1 + a_1
#define a_ref(a_1,a_2) a[a_subscr(a_1,a_2)]


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

    /* Function Body */
    *info = 0;
    upper = lsame_(uplo, "U");
    if (! upper && ! lsame_(uplo, "L")) {
	*info = -1;
    } else if (*n < 0) {
	*info = -2;
    } else if (*lda < max(1,*n)) {
	*info = -4;
    } else if (*anorm < 0.f) {
	*info = -6;
    }
    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("CSYCON", &i__1);
	return 0;
    }

/*     Quick return if possible */

    *rcond = 0.f;
    if (*n == 0) {
	*rcond = 1.f;
	return 0;
    } else if (*anorm <= 0.f) {
	return 0;
    }

/*     Check that the diagonal matrix D is nonsingular. */

    if (upper) {

/*        Upper triangular storage: examine D from bottom to top */

	for (i__ = *n; i__ >= 1; --i__) {
	    i__1 = a_subscr(i__, i__);
	    if (ipiv[i__] > 0 && (a[i__1].r == 0.f && a[i__1].i == 0.f)) {
		return 0;
	    }
/* L10: */
	}
    } else {

/*        Lower triangular storage: examine D from top to bottom. */

	i__1 = *n;
	for (i__ = 1; i__ <= i__1; ++i__) {
	    i__2 = a_subscr(i__, i__);
	    if (ipiv[i__] > 0 && (a[i__2].r == 0.f && a[i__2].i == 0.f)) {
		return 0;
	    }
/* L20: */
	}
    }

/*     Estimate the 1-norm of the inverse. */

    kase = 0;
L30:
    clacon_(n, &work[*n + 1], &work[1], &ainvnm, &kase);
    if (kase != 0) {

/*        Multiply by inv(L*D*L') or inv(U*D*U'). */

	csytrs_(uplo, n, &c__1, &a[a_offset], lda, &ipiv[1], &work[1], n, 
		info);
	goto L30;
    }

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

    if (ainvnm != 0.f) {
	*rcond = 1.f / ainvnm / *anorm;
    }

    return 0;

/*     End of CSYCON */

} /* csycon_ */
Пример #9
0
/* Subroutine */ int cla_syrfsx_extended__(integer *prec_type__, char *uplo, 
	integer *n, integer *nrhs, complex *a, integer *lda, complex *af, 
	integer *ldaf, integer *ipiv, logical *colequ, real *c__, complex *b, 
	integer *ldb, complex *y, integer *ldy, real *berr_out__, integer *
	n_norms__, real *err_bnds_norm__, real *err_bnds_comp__, complex *res,
	 real *ayb, complex *dy, complex *y_tail__, real *rcond, integer *
	ithresh, real *rthresh, real *dz_ub__, logical *ignore_cwise__, 
	integer *info, ftnlen uplo_len)
{
    /* System generated locals */
    integer a_dim1, a_offset, af_dim1, af_offset, b_dim1, b_offset, y_dim1, 
	    y_offset, err_bnds_norm_dim1, err_bnds_norm_offset, 
	    err_bnds_comp_dim1, err_bnds_comp_offset, i__1, i__2, i__3, i__4;
    real r__1, r__2;

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

    /* Local variables */
    real dxratmax, dzratmax;
    integer i__, j;
    logical incr_prec__;
    extern /* Subroutine */ int cla_syamv__(integer *, integer *, real *, 
	    complex *, integer *, complex *, integer *, real *, real *, 
	    integer *);
    real prev_dz_z__, yk, final_dx_x__;
    extern /* Subroutine */ int cla_wwaddw__(integer *, complex *, complex *, 
	    complex *);
    real final_dz_z__, prevnormdx;
    integer cnt;
    real dyk, eps, incr_thresh__, dx_x__, dz_z__;
    extern /* Subroutine */ int cla_lin_berr__(integer *, integer *, integer *
	    , complex *, real *, real *);
    real ymin;
    integer y_prec_state__;
    extern /* Subroutine */ int blas_csymv_x__(integer *, integer *, complex *
	    , complex *, integer *, complex *, integer *, complex *, complex *
	    , integer *, integer *);
    integer uplo2;
    extern logical lsame_(char *, char *);
    extern /* Subroutine */ int blas_csymv2_x__(integer *, integer *, complex 
	    *, complex *, integer *, complex *, complex *, integer *, complex 
	    *, complex *, integer *, integer *), ccopy_(integer *, complex *, 
	    integer *, complex *, integer *);
    real dxrat, dzrat;
    extern /* Subroutine */ int caxpy_(integer *, complex *, complex *, 
	    integer *, complex *, integer *), csymv_(char *, integer *, 
	    complex *, complex *, integer *, complex *, integer *, complex *, 
	    complex *, integer *);
    real normx, normy;
    extern doublereal slamch_(char *);
    real normdx;
    extern /* Subroutine */ int csytrs_(char *, integer *, integer *, complex 
	    *, integer *, integer *, complex *, integer *, integer *);
    real hugeval;
    extern integer ilauplo_(char *);
    integer x_state__, z_state__;


/*     -- LAPACK routine (version 3.2.1)                                 -- */
/*     -- Contributed by James Demmel, Deaglan Halligan, Yozo Hida and -- */
/*     -- Jason Riedy of Univ. of California Berkeley.                 -- */
/*     -- April 2009                                                   -- */

/*     -- LAPACK is a software package provided by Univ. of Tennessee, -- */
/*     -- Univ. of California Berkeley and NAG Ltd.                    -- */

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

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

/*  CLA_SYRFSX_EXTENDED improves the computed solution to a system of */
/*  linear equations by performing extra-precise iterative refinement */
/*  and provides error bounds and backward error estimates for the solution. */
/*  This subroutine is called by CSYRFSX to perform iterative refinement. */
/*  In addition to normwise error bound, the code provides maximum */
/*  componentwise error bound if possible. See comments for ERR_BNDS_NORM */
/*  and ERR_BNDS_COMP for details of the error bounds. Note that this */
/*  subroutine is only resonsible for setting the second fields of */
/*  ERR_BNDS_NORM and ERR_BNDS_COMP. */

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

/*     PREC_TYPE      (input) INTEGER */
/*     Specifies the intermediate precision to be used in refinement. */
/*     The value is defined by ILAPREC(P) where P is a CHARACTER and */
/*     P    = 'S':  Single */
/*          = 'D':  Double */
/*          = 'I':  Indigenous */
/*          = 'X', 'E':  Extra */

/*     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. */

/*     NRHS           (input) INTEGER */
/*     The number of right-hand-sides, i.e., the number of columns of the */
/*     matrix B. */

/*     A              (input) COMPLEX array, dimension (LDA,N) */
/*     On entry, the N-by-N matrix A. */

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

/*     AF             (input) COMPLEX array, dimension (LDAF,N) */
/*     The block diagonal matrix D and the multipliers used to */
/*     obtain the factor U or L as computed by CSYTRF. */

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

/*     IPIV           (input) INTEGER array, dimension (N) */
/*     Details of the interchanges and the block structure of D */
/*     as determined by CSYTRF. */

/*     COLEQU         (input) LOGICAL */
/*     If .TRUE. then column equilibration was done to A before calling */
/*     this routine. This is needed to compute the solution and error */
/*     bounds correctly. */

/*     C              (input) REAL array, dimension (N) */
/*     The column scale factors for A. If COLEQU = .FALSE., C */
/*     is not accessed. If C is input, each element of C should be a power */
/*     of the radix to ensure a reliable solution and error estimates. */
/*     Scaling by powers of the radix does not cause rounding errors unless */
/*     the result underflows or overflows. Rounding errors during scaling */
/*     lead to refining with a matrix that is not equivalent to the */
/*     input matrix, producing error estimates that may not be */
/*     reliable. */

/*     B              (input) COMPLEX array, dimension (LDB,NRHS) */
/*     The right-hand-side matrix B. */

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

/*     Y              (input/output) COMPLEX array, dimension */
/*                    (LDY,NRHS) */
/*     On entry, the solution matrix X, as computed by CSYTRS. */
/*     On exit, the improved solution matrix Y. */

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

/*     BERR_OUT       (output) REAL array, dimension (NRHS) */
/*     On exit, BERR_OUT(j) contains the componentwise relative backward */
/*     error for right-hand-side j from the formula */
/*         max(i) ( abs(RES(i)) / ( abs(op(A_s))*abs(Y) + abs(B_s) )(i) ) */
/*     where abs(Z) is the componentwise absolute value of the matrix */
/*     or vector Z. This is computed by CLA_LIN_BERR. */

/*     N_NORMS        (input) INTEGER */
/*     Determines which error bounds to return (see ERR_BNDS_NORM */
/*     and ERR_BNDS_COMP). */
/*     If N_NORMS >= 1 return normwise error bounds. */
/*     If N_NORMS >= 2 return componentwise error bounds. */

/*     ERR_BNDS_NORM  (input/output) REAL array, dimension */
/*                    (NRHS, N_ERR_BNDS) */
/*     For each right-hand side, this array contains information about */
/*     various error bounds and condition numbers corresponding to the */
/*     normwise relative error, which is defined as follows: */

/*     Normwise relative error in the ith solution vector: */
/*             max_j (abs(XTRUE(j,i) - X(j,i))) */
/*            ------------------------------ */
/*                  max_j abs(X(j,i)) */

/*     The array is indexed by the type of error information as described */
/*     below. There currently are up to three pieces of information */
/*     returned. */

/*     The first index in ERR_BNDS_NORM(i,:) corresponds to the ith */
/*     right-hand side. */

/*     The second index in ERR_BNDS_NORM(:,err) contains the following */
/*     three fields: */
/*     err = 1 "Trust/don't trust" boolean. Trust the answer if the */
/*              reciprocal condition number is less than the threshold */
/*              sqrt(n) * slamch('Epsilon'). */

/*     err = 2 "Guaranteed" error bound: The estimated forward error, */
/*              almost certainly within a factor of 10 of the true error */
/*              so long as the next entry is greater than the threshold */
/*              sqrt(n) * slamch('Epsilon'). This error bound should only */
/*              be trusted if the previous boolean is true. */

/*     err = 3  Reciprocal condition number: Estimated normwise */
/*              reciprocal condition number.  Compared with the threshold */
/*              sqrt(n) * slamch('Epsilon') to determine if the error */
/*              estimate is "guaranteed". These reciprocal condition */
/*              numbers are 1 / (norm(Z^{-1},inf) * norm(Z,inf)) for some */
/*              appropriately scaled matrix Z. */
/*              Let Z = S*A, where S scales each row by a power of the */
/*              radix so all absolute row sums of Z are approximately 1. */

/*     This subroutine is only responsible for setting the second field */
/*     above. */
/*     See Lapack Working Note 165 for further details and extra */
/*     cautions. */

/*     ERR_BNDS_COMP  (input/output) REAL array, dimension */
/*                    (NRHS, N_ERR_BNDS) */
/*     For each right-hand side, this array contains information about */
/*     various error bounds and condition numbers corresponding to the */
/*     componentwise relative error, which is defined as follows: */

/*     Componentwise relative error in the ith solution vector: */
/*                    abs(XTRUE(j,i) - X(j,i)) */
/*             max_j ---------------------- */
/*                         abs(X(j,i)) */

/*     The array is indexed by the right-hand side i (on which the */
/*     componentwise relative error depends), and the type of error */
/*     information as described below. There currently are up to three */
/*     pieces of information returned for each right-hand side. If */
/*     componentwise accuracy is not requested (PARAMS(3) = 0.0), then */
/*     ERR_BNDS_COMP is not accessed.  If N_ERR_BNDS .LT. 3, then at most */
/*     the first (:,N_ERR_BNDS) entries are returned. */

/*     The first index in ERR_BNDS_COMP(i,:) corresponds to the ith */
/*     right-hand side. */

/*     The second index in ERR_BNDS_COMP(:,err) contains the following */
/*     three fields: */
/*     err = 1 "Trust/don't trust" boolean. Trust the answer if the */
/*              reciprocal condition number is less than the threshold */
/*              sqrt(n) * slamch('Epsilon'). */

/*     err = 2 "Guaranteed" error bound: The estimated forward error, */
/*              almost certainly within a factor of 10 of the true error */
/*              so long as the next entry is greater than the threshold */
/*              sqrt(n) * slamch('Epsilon'). This error bound should only */
/*              be trusted if the previous boolean is true. */

/*     err = 3  Reciprocal condition number: Estimated componentwise */
/*              reciprocal condition number.  Compared with the threshold */
/*              sqrt(n) * slamch('Epsilon') to determine if the error */
/*              estimate is "guaranteed". These reciprocal condition */
/*              numbers are 1 / (norm(Z^{-1},inf) * norm(Z,inf)) for some */
/*              appropriately scaled matrix Z. */
/*              Let Z = S*(A*diag(x)), where x is the solution for the */
/*              current right-hand side and S scales each row of */
/*              A*diag(x) by a power of the radix so all absolute row */
/*              sums of Z are approximately 1. */

/*     This subroutine is only responsible for setting the second field */
/*     above. */
/*     See Lapack Working Note 165 for further details and extra */
/*     cautions. */

/*     RES            (input) COMPLEX array, dimension (N) */
/*     Workspace to hold the intermediate residual. */

/*     AYB            (input) REAL array, dimension (N) */
/*     Workspace. */

/*     DY             (input) COMPLEX array, dimension (N) */
/*     Workspace to hold the intermediate solution. */

/*     Y_TAIL         (input) COMPLEX array, dimension (N) */
/*     Workspace to hold the trailing bits of the intermediate solution. */

/*     RCOND          (input) REAL */
/*     Reciprocal scaled condition number.  This is an estimate of the */
/*     reciprocal Skeel condition number of the matrix A after */
/*     equilibration (if done).  If this is less than the machine */
/*     precision (in particular, if it is zero), the matrix is singular */
/*     to working precision.  Note that the error may still be small even */
/*     if this number is very small and the matrix appears ill- */
/*     conditioned. */

/*     ITHRESH        (input) INTEGER */
/*     The maximum number of residual computations allowed for */
/*     refinement. The default is 10. For 'aggressive' set to 100 to */
/*     permit convergence using approximate factorizations or */
/*     factorizations other than LU. If the factorization uses a */
/*     technique other than Gaussian elimination, the guarantees in */
/*     ERR_BNDS_NORM and ERR_BNDS_COMP may no longer be trustworthy. */

/*     RTHRESH        (input) REAL */
/*     Determines when to stop refinement if the error estimate stops */
/*     decreasing. Refinement will stop when the next solution no longer */
/*     satisfies norm(dx_{i+1}) < RTHRESH * norm(dx_i) where norm(Z) is */
/*     the infinity norm of Z. RTHRESH satisfies 0 < RTHRESH <= 1. The */
/*     default value is 0.5. For 'aggressive' set to 0.9 to permit */
/*     convergence on extremely ill-conditioned matrices. See LAWN 165 */
/*     for more details. */

/*     DZ_UB          (input) REAL */
/*     Determines when to start considering componentwise convergence. */
/*     Componentwise convergence is only considered after each component */
/*     of the solution Y is stable, which we definte as the relative */
/*     change in each component being less than DZ_UB. The default value */
/*     is 0.25, requiring the first bit to be stable. See LAWN 165 for */
/*     more details. */

/*     IGNORE_CWISE   (input) LOGICAL */
/*     If .TRUE. then ignore componentwise convergence. Default value */
/*     is .FALSE.. */

/*     INFO           (output) INTEGER */
/*       = 0:  Successful exit. */
/*       < 0:  if INFO = -i, the ith argument to CSYTRS had an illegal */
/*             value */

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

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

    /* Parameter adjustments */
    err_bnds_comp_dim1 = *nrhs;
    err_bnds_comp_offset = 1 + err_bnds_comp_dim1;
    err_bnds_comp__ -= err_bnds_comp_offset;
    err_bnds_norm_dim1 = *nrhs;
    err_bnds_norm_offset = 1 + err_bnds_norm_dim1;
    err_bnds_norm__ -= err_bnds_norm_offset;
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    af_dim1 = *ldaf;
    af_offset = 1 + af_dim1;
    af -= af_offset;
    --ipiv;
    --c__;
    b_dim1 = *ldb;
    b_offset = 1 + b_dim1;
    b -= b_offset;
    y_dim1 = *ldy;
    y_offset = 1 + y_dim1;
    y -= y_offset;
    --berr_out__;
    --res;
    --ayb;
    --dy;
    --y_tail__;

    /* Function Body */
    if (*info != 0) {
	return 0;
    }
    eps = slamch_("Epsilon");
    hugeval = slamch_("Overflow");
/*     Force HUGEVAL to Inf */
    hugeval *= hugeval;
/*     Using HUGEVAL may lead to spurious underflows. */
    incr_thresh__ = (real) (*n) * eps;
    if (lsame_(uplo, "L")) {
	uplo2 = ilauplo_("L");
    } else {
	uplo2 = ilauplo_("U");
    }
    i__1 = *nrhs;
    for (j = 1; j <= i__1; ++j) {
	y_prec_state__ = 1;
	if (y_prec_state__ == 2) {
	    i__2 = *n;
	    for (i__ = 1; i__ <= i__2; ++i__) {
		i__3 = i__;
		y_tail__[i__3].r = 0.f, y_tail__[i__3].i = 0.f;
	    }
	}
	dxrat = 0.f;
	dxratmax = 0.f;
	dzrat = 0.f;
	dzratmax = 0.f;
	final_dx_x__ = hugeval;
	final_dz_z__ = hugeval;
	prevnormdx = hugeval;
	prev_dz_z__ = hugeval;
	dz_z__ = hugeval;
	dx_x__ = hugeval;
	x_state__ = 1;
	z_state__ = 0;
	incr_prec__ = FALSE_;
	i__2 = *ithresh;
	for (cnt = 1; cnt <= i__2; ++cnt) {

/*         Compute residual RES = B_s - op(A_s) * Y, */
/*             op(A) = A, A**T, or A**H depending on TRANS (and type). */

	    ccopy_(n, &b[j * b_dim1 + 1], &c__1, &res[1], &c__1);
	    if (y_prec_state__ == 0) {
		csymv_(uplo, n, &c_b11, &a[a_offset], lda, &y[j * y_dim1 + 1], 
			 &c__1, &c_b12, &res[1], &c__1);
	    } else if (y_prec_state__ == 1) {
		blas_csymv_x__(&uplo2, n, &c_b11, &a[a_offset], lda, &y[j * 
			y_dim1 + 1], &c__1, &c_b12, &res[1], &c__1, 
			prec_type__);
	    } else {
		blas_csymv2_x__(&uplo2, n, &c_b11, &a[a_offset], lda, &y[j * 
			y_dim1 + 1], &y_tail__[1], &c__1, &c_b12, &res[1], &
			c__1, prec_type__);
	    }
/*         XXX: RES is no longer needed. */
	    ccopy_(n, &res[1], &c__1, &dy[1], &c__1);
	    csytrs_(uplo, n, nrhs, &af[af_offset], ldaf, &ipiv[1], &dy[1], n, 
		    info);

/*         Calculate relative changes DX_X, DZ_Z and ratios DXRAT, DZRAT. */

	    normx = 0.f;
	    normy = 0.f;
	    normdx = 0.f;
	    dz_z__ = 0.f;
	    ymin = hugeval;
	    i__3 = *n;
	    for (i__ = 1; i__ <= i__3; ++i__) {
		i__4 = i__ + j * y_dim1;
		yk = (r__1 = y[i__4].r, dabs(r__1)) + (r__2 = r_imag(&y[i__ + 
			j * y_dim1]), dabs(r__2));
		i__4 = i__;
		dyk = (r__1 = dy[i__4].r, dabs(r__1)) + (r__2 = r_imag(&dy[
			i__]), dabs(r__2));
		if (yk != 0.f) {
/* Computing MAX */
		    r__1 = dz_z__, r__2 = dyk / yk;
		    dz_z__ = dmax(r__1,r__2);
		} else if (dyk != 0.f) {
		    dz_z__ = hugeval;
		}
		ymin = dmin(ymin,yk);
		normy = dmax(normy,yk);
		if (*colequ) {
/* Computing MAX */
		    r__1 = normx, r__2 = yk * c__[i__];
		    normx = dmax(r__1,r__2);
/* Computing MAX */
		    r__1 = normdx, r__2 = dyk * c__[i__];
		    normdx = dmax(r__1,r__2);
		} else {
		    normx = normy;
		    normdx = dmax(normdx,dyk);
		}
	    }
	    if (normx != 0.f) {
		dx_x__ = normdx / normx;
	    } else if (normdx == 0.f) {
		dx_x__ = 0.f;
	    } else {
		dx_x__ = hugeval;
	    }
	    dxrat = normdx / prevnormdx;
	    dzrat = dz_z__ / prev_dz_z__;

/*         Check termination criteria. */

	    if (ymin * *rcond < incr_thresh__ * normy && y_prec_state__ < 2) {
		incr_prec__ = TRUE_;
	    }
	    if (x_state__ == 3 && dxrat <= *rthresh) {
		x_state__ = 1;
	    }
	    if (x_state__ == 1) {
		if (dx_x__ <= eps) {
		    x_state__ = 2;
		} else if (dxrat > *rthresh) {
		    if (y_prec_state__ != 2) {
			incr_prec__ = TRUE_;
		    } else {
			x_state__ = 3;
		    }
		} else {
		    if (dxrat > dxratmax) {
			dxratmax = dxrat;
		    }
		}
		if (x_state__ > 1) {
		    final_dx_x__ = dx_x__;
		}
	    }
	    if (z_state__ == 0 && dz_z__ <= *dz_ub__) {
		z_state__ = 1;
	    }
	    if (z_state__ == 3 && dzrat <= *rthresh) {
		z_state__ = 1;
	    }
	    if (z_state__ == 1) {
		if (dz_z__ <= eps) {
		    z_state__ = 2;
		} else if (dz_z__ > *dz_ub__) {
		    z_state__ = 0;
		    dzratmax = 0.f;
		    final_dz_z__ = hugeval;
		} else if (dzrat > *rthresh) {
		    if (y_prec_state__ != 2) {
			incr_prec__ = TRUE_;
		    } else {
			z_state__ = 3;
		    }
		} else {
		    if (dzrat > dzratmax) {
			dzratmax = dzrat;
		    }
		}
		if (z_state__ > 1) {
		    final_dz_z__ = dz_z__;
		}
	    }
	    if (x_state__ != 1 && (*ignore_cwise__ || z_state__ != 1)) {
		goto L666;
	    }
	    if (incr_prec__) {
		incr_prec__ = FALSE_;
		++y_prec_state__;
		i__3 = *n;
		for (i__ = 1; i__ <= i__3; ++i__) {
		    i__4 = i__;
		    y_tail__[i__4].r = 0.f, y_tail__[i__4].i = 0.f;
		}
	    }
	    prevnormdx = normdx;
	    prev_dz_z__ = dz_z__;

/*           Update soluton. */

	    if (y_prec_state__ < 2) {
		caxpy_(n, &c_b12, &dy[1], &c__1, &y[j * y_dim1 + 1], &c__1);
	    } else {
		cla_wwaddw__(n, &y[j * y_dim1 + 1], &y_tail__[1], &dy[1]);
	    }
	}
/*        Target of "IF (Z_STOP .AND. X_STOP)".  Sun's f77 won't EXIT. */
L666:

/*     Set final_* when cnt hits ithresh. */

	if (x_state__ == 1) {
	    final_dx_x__ = dx_x__;
	}
	if (z_state__ == 1) {
	    final_dz_z__ = dz_z__;
	}

/*     Compute error bounds. */

	if (*n_norms__ >= 1) {
	    err_bnds_norm__[j + (err_bnds_norm_dim1 << 1)] = final_dx_x__ / (
		    1 - dxratmax);
	}
	if (*n_norms__ >= 2) {
	    err_bnds_comp__[j + (err_bnds_comp_dim1 << 1)] = final_dz_z__ / (
		    1 - dzratmax);
	}

/*     Compute componentwise relative backward error from formula */
/*         max(i) ( abs(R(i)) / ( abs(op(A_s))*abs(Y) + abs(B_s) )(i) ) */
/*     where abs(Z) is the componentwise absolute value of the matrix */
/*     or vector Z. */

/*        Compute residual RES = B_s - op(A_s) * Y, */
/*            op(A) = A, A**T, or A**H depending on TRANS (and type). */

	ccopy_(n, &b[j * b_dim1 + 1], &c__1, &res[1], &c__1);
	csymv_(uplo, n, &c_b11, &a[a_offset], lda, &y[j * y_dim1 + 1], &c__1, 
		&c_b12, &res[1], &c__1);
	i__2 = *n;
	for (i__ = 1; i__ <= i__2; ++i__) {
	    i__3 = i__ + j * b_dim1;
	    ayb[i__] = (r__1 = b[i__3].r, dabs(r__1)) + (r__2 = r_imag(&b[i__ 
		    + j * b_dim1]), dabs(r__2));
	}

/*     Compute abs(op(A_s))*abs(Y) + abs(B_s). */

	cla_syamv__(&uplo2, n, &c_b33, &a[a_offset], lda, &y[j * y_dim1 + 1], 
		&c__1, &c_b33, &ayb[1], &c__1);
	cla_lin_berr__(n, n, &c__1, &res[1], &ayb[1], &berr_out__[j]);

/*     End of loop for each RHS. */

    }

    return 0;
} /* cla_syrfsx_extended__ */
Пример #10
0
/* Subroutine */ int cchksy_(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 *iwork, integer *nout)
{
    /* Initialized data */

    static integer iseedy[4] = { 1988,1989,1990,1991 };
    static char uplos[1*2] = "U" "L";

    /* Format strings */
    static char fmt_9999[] = "(\002 UPLO = '\002,a1,\002', N =\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, "
	    "NRHS=\002,i3,\002, type \002,i2,\002, test(\002,i2,\002) =\002,g"
	    "12.5)";
    static char fmt_9997[] = "(\002 UPLO = '\002,a1,\002', N =\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;

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

    /* Local variables */
    integer i__, j, k, n, i1, i2, nb, in, kl, ku, nt, lda, inb, ioff, mode, 
	    imat, info;
    char path[3], dist[1];
    integer irhs, nrhs;
    char uplo[1], type__[1];
    integer nrun;
    extern /* Subroutine */ int alahd_(integer *, char *), cget04_(
	    integer *, integer *, complex *, integer *, complex *, integer *, 
	    real *, real *);
    integer nfail, iseed[4];
    real rcond;
    integer nimat;
    extern doublereal sget06_(real *, real *);
    extern /* Subroutine */ int cpot05_(char *, integer *, integer *, complex 
	    *, integer *, complex *, integer *, complex *, integer *, complex 
	    *, integer *, real *, real *, real *);
    real anorm;
    extern /* Subroutine */ int csyt01_(char *, integer *, complex *, integer 
	    *, complex *, integer *, integer *, complex *, integer *, real *, 
	    real *), csyt02_(char *, integer *, integer *, complex *, 
	    integer *, complex *, integer *, complex *, integer *, real *, 
	    real *), csyt03_(char *, integer *, complex *, integer *, 
	    complex *, integer *, complex *, integer *, real *, real *, real *
);
    integer iuplo, izero, nerrs, lwork;
    logical zerot;
    char xtype[1];
    extern /* Subroutine */ int clatb4_(char *, integer *, integer *, integer 
	    *, char *, integer *, integer *, real *, integer *, real *, char *
), alaerh_(char *, char *, integer *, 
	    integer *, char *, integer *, integer *, integer *, integer *, 
	    integer *, integer *, integer *, integer *, integer *);
    real rcondc;
    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 *), 
	    alasum_(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 *);
    extern doublereal clansy_(char *, char *, integer *, complex *, integer *, 
	     real *);
    logical trfcon;
    extern /* Subroutine */ int csycon_(char *, integer *, complex *, integer 
	    *, integer *, real *, real *, complex *, integer *), 
	    clatsy_(char *, integer *, complex *, integer *, integer *), xlaenv_(integer *, integer *), cerrsy_(char *, integer *), csyrfs_(char *, integer *, integer *, complex *, 
	    integer *, complex *, integer *, integer *, complex *, integer *, 
	    complex *, integer *, real *, real *, complex *, real *, integer *
), csytrf_(char *, integer *, complex *, integer *, 
	    integer *, complex *, integer *, integer *), csytri_(char 
	    *, integer *, complex *, integer *, integer *, complex *, integer 
	    *);
    real result[8];
    extern /* Subroutine */ int csytrs_(char *, integer *, integer *, complex 
	    *, integer *, integer *, complex *, integer *, integer *);

    /* Fortran I/O blocks */
    static cilist io___39 = { 0, 0, 0, fmt_9999, 0 };
    static cilist io___42 = { 0, 0, 0, fmt_9998, 0 };
    static cilist io___44 = { 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 */
/*  ======= */

/*  CCHKSY tests CSYTRF, -TRI, -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) COMPLEX array, dimension (NMAX*NMAX) */

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

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

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

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

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

/*  WORK    (workspace) COMPLEX array, dimension */
/*                      (NMAX*max(2,NSMAX)) */

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

/*  IWORK   (workspace) INTEGER array, dimension (NMAX) */

/*  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 */
    --iwork;
    --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, "SY", (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) {
	cerrsy_(path, nout);
    }
    infoc_1.infot = 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';
	nimat = 11;
	if (n <= 0) {
	    nimat = 1;
	}

	izero = 0;
	i__2 = nimat;
	for (imat = 1; imat <= i__2; ++imat) {

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

	    if (! dotype[imat]) {
		goto L170;
	    }

/*           Skip types 3, 4, 5, or 6 if the matrix size is too small. */

	    zerot = imat >= 3 && imat <= 6;
	    if (zerot && n < imat - 2) {
		goto L170;
	    }

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

	    for (iuplo = 1; iuplo <= 2; ++iuplo) {
		*(unsigned char *)uplo = *(unsigned char *)&uplos[iuplo - 1];

		if (imat != 11) {

/*                 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, &kl, &ku, "N", &a[1], &lda, &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 L160;
		    }

/*                 For types 3-6, zero one or more rows and columns of */
/*                 the matrix to test that INFO is returned correctly. */

		    if (zerot) {
			if (imat == 3) {
			    izero = 1;
			} else if (imat == 4) {
			    izero = n;
			} else {
			    izero = n / 2 + 1;
			}

			if (imat < 6) {

/*                       Set row and column IZERO to zero. */

			    if (iuplo == 1) {
				ioff = (izero - 1) * lda;
				i__3 = izero - 1;
				for (i__ = 1; i__ <= i__3; ++i__) {
				    i__4 = ioff + i__;
				    a[i__4].r = 0.f, a[i__4].i = 0.f;
/* L20: */
				}
				ioff += izero;
				i__3 = n;
				for (i__ = izero; i__ <= i__3; ++i__) {
				    i__4 = ioff;
				    a[i__4].r = 0.f, a[i__4].i = 0.f;
				    ioff += lda;
/* L30: */
				}
			    } else {
				ioff = izero;
				i__3 = izero - 1;
				for (i__ = 1; i__ <= i__3; ++i__) {
				    i__4 = ioff;
				    a[i__4].r = 0.f, a[i__4].i = 0.f;
				    ioff += lda;
/* L40: */
				}
				ioff -= izero;
				i__3 = n;
				for (i__ = izero; i__ <= i__3; ++i__) {
				    i__4 = ioff + i__;
				    a[i__4].r = 0.f, a[i__4].i = 0.f;
/* L50: */
				}
			    }
			} else {
			    if (iuplo == 1) {

/*                          Set the first IZERO rows to zero. */

				ioff = 0;
				i__3 = n;
				for (j = 1; j <= i__3; ++j) {
				    i2 = min(j,izero);
				    i__4 = i2;
				    for (i__ = 1; i__ <= i__4; ++i__) {
					i__5 = ioff + i__;
					a[i__5].r = 0.f, a[i__5].i = 0.f;
/* L60: */
				    }
				    ioff += lda;
/* L70: */
				}
			    } else {

/*                          Set the last IZERO rows to zero. */

				ioff = 0;
				i__3 = n;
				for (j = 1; j <= i__3; ++j) {
				    i1 = max(j,izero);
				    i__4 = n;
				    for (i__ = i1; i__ <= i__4; ++i__) {
					i__5 = ioff + i__;
					a[i__5].r = 0.f, a[i__5].i = 0.f;
/* L80: */
				    }
				    ioff += lda;
/* L90: */
				}
			    }
			}
		    } else {
			izero = 0;
		    }
		} else {

/*                 Use a special block diagonal matrix to test alternate */
/*                 code for the 2 x 2 blocks. */

		    clatsy_(uplo, &n, &a[1], &lda, iseed);
		}

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

		i__3 = *nnb;
		for (inb = 1; inb <= i__3; ++inb) {
		    nb = nbval[inb];
		    xlaenv_(&c__1, &nb);

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

		    clacpy_(uplo, &n, &n, &a[1], &lda, &afac[1], &lda);
		    lwork = max(2,nb) * lda;
		    s_copy(srnamc_1.srnamt, "CSYTRF", (ftnlen)6, (ftnlen)6);
		    csytrf_(uplo, &n, &afac[1], &lda, &iwork[1], &ainv[1], &
			    lwork, &info);

/*                 Adjust the expected value of INFO to account for */
/*                 pivoting. */

		    k = izero;
		    if (k > 0) {
L100:
			if (iwork[k] < 0) {
			    if (iwork[k] != -k) {
				k = -iwork[k];
				goto L100;
			    }
			} else if (iwork[k] != k) {
			    k = iwork[k];
			    goto L100;
			}
		    }

/*                 Check error code from CSYTRF. */

		    if (info != k) {
			alaerh_(path, "CSYTRF", &info, &k, uplo, &n, &n, &
				c_n1, &c_n1, &nb, &imat, &nfail, &nerrs, nout);
		    }
		    if (info != 0) {
			trfcon = TRUE_;
		    } else {
			trfcon = FALSE_;
		    }

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

		    csyt01_(uplo, &n, &a[1], &lda, &afac[1], &lda, &iwork[1], 
			    &ainv[1], &lda, &rwork[1], result);
		    nt = 1;

/* +    TEST 2 */
/*                 Form the inverse and compute the residual. */

		    if (inb == 1 && ! trfcon) {
			clacpy_(uplo, &n, &n, &afac[1], &lda, &ainv[1], &lda);
			s_copy(srnamc_1.srnamt, "CSYTRI", (ftnlen)6, (ftnlen)
				6);
			csytri_(uplo, &n, &ainv[1], &lda, &iwork[1], &work[1], 
				 &info);

/*                 Check error code from CSYTRI. */

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

			csyt03_(uplo, &n, &a[1], &lda, &ainv[1], &lda, &work[
				1], &lda, &rwork[1], &rcondc, &result[1]);
			nt = 2;
		    }

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

		    i__4 = nt;
		    for (k = 1; k <= i__4; ++k) {
			if (result[k - 1] >= *thresh) {
			    if (nfail == 0 && nerrs == 0) {
				alahd_(nout, path);
			    }
			    io___39.ciunit = *nout;
			    s_wsfe(&io___39);
			    do_fio(&c__1, uplo, (ftnlen)1);
			    do_fio(&c__1, (char *)&n, (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 *)&k, (ftnlen)sizeof(integer))
				    ;
			    do_fio(&c__1, (char *)&result[k - 1], (ftnlen)
				    sizeof(real));
			    e_wsfe();
			    ++nfail;
			}
/* L110: */
		    }
		    nrun += nt;

/*                 Skip the other tests if this is not the first block */
/*                 size. */

		    if (inb > 1) {
			goto L150;
		    }

/*                 Do only the condition estimate if INFO is not 0. */

		    if (trfcon) {
			rcondc = 0.f;
			goto L140;
		    }

		    i__4 = *nns;
		    for (irhs = 1; irhs <= i__4; ++irhs) {
			nrhs = nsval[irhs];

/* +    TEST 3 */
/*                 Solve and compute residual for  A * X = B. */

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

			s_copy(srnamc_1.srnamt, "CSYTRS", (ftnlen)6, (ftnlen)
				6);
			csytrs_(uplo, &n, &nrhs, &afac[1], &lda, &iwork[1], &
				x[1], &lda, &info);

/*                 Check error code from CSYTRS. */

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

			clacpy_("Full", &n, &nrhs, &b[1], &lda, &work[1], &
				lda);
			csyt02_(uplo, &n, &nrhs, &a[1], &lda, &x[1], &lda, &
				work[1], &lda, &rwork[1], &result[2]);

/* +    TEST 4 */
/*                 Check solution from generated exact solution. */

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

/* +    TESTS 5, 6, and 7 */
/*                 Use iterative refinement to improve the solution. */

			s_copy(srnamc_1.srnamt, "CSYRFS", (ftnlen)6, (ftnlen)
				6);
			csyrfs_(uplo, &n, &nrhs, &a[1], &lda, &afac[1], &lda, 
				&iwork[1], &b[1], &lda, &x[1], &lda, &rwork[1]
, &rwork[nrhs + 1], &work[1], &rwork[(nrhs << 
				1) + 1], &info);

/*                 Check error code from CSYRFS. */

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

			cget04_(&n, &nrhs, &x[1], &lda, &xact[1], &lda, &
				rcondc, &result[4]);
			cpot05_(uplo, &n, &nrhs, &a[1], &lda, &b[1], &lda, &x[
				1], &lda, &xact[1], &lda, &rwork[1], &rwork[
				nrhs + 1], &result[5]);

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

			for (k = 3; k <= 7; ++k) {
			    if (result[k - 1] >= *thresh) {
				if (nfail == 0 && nerrs == 0) {
				    alahd_(nout, path);
				}
				io___42.ciunit = *nout;
				s_wsfe(&io___42);
				do_fio(&c__1, uplo, (ftnlen)1);
				do_fio(&c__1, (char *)&n, (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;
			    }
/* L120: */
			}
			nrun += 5;
/* L130: */
		    }

/* +    TEST 8 */
/*                 Get an estimate of RCOND = 1/CNDNUM. */

L140:
		    anorm = clansy_("1", uplo, &n, &a[1], &lda, &rwork[1]);
		    s_copy(srnamc_1.srnamt, "CSYCON", (ftnlen)6, (ftnlen)6);
		    csycon_(uplo, &n, &afac[1], &lda, &iwork[1], &anorm, &
			    rcond, &work[1], &info);

/*                 Check error code from CSYCON. */

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

		    result[7] = sget06_(&rcond, &rcondc);

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

		    if (result[7] >= *thresh) {
			if (nfail == 0 && nerrs == 0) {
			    alahd_(nout, path);
			}
			io___44.ciunit = *nout;
			s_wsfe(&io___44);
			do_fio(&c__1, uplo, (ftnlen)1);
			do_fio(&c__1, (char *)&n, (ftnlen)sizeof(integer));
			do_fio(&c__1, (char *)&imat, (ftnlen)sizeof(integer));
			do_fio(&c__1, (char *)&c__8, (ftnlen)sizeof(integer));
			do_fio(&c__1, (char *)&result[7], (ftnlen)sizeof(real)
				);
			e_wsfe();
			++nfail;
		    }
		    ++nrun;
L150:
		    ;
		}
L160:
		;
	    }
L170:
	    ;
	}
/* L180: */
    }

/*     Print a summary of the results. */

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

    return 0;

/*     End of CCHKSY */

} /* cchksy_ */