Example #1
0
/* Subroutine */ int ctrcon_(char *norm, char *uplo, char *diag, integer *n, 
	complex *a, integer *lda, real *rcond, complex *work, real *rwork, 
	integer *info)
{
    /* System generated locals */
    integer a_dim1, a_offset, i__1;
    real r__1, r__2;

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

    /* Local variables */
    integer ix, kase, kase1;
    real scale;
    extern logical lsame_(char *, char *);
    integer isave[3];
    real anorm;
    logical upper;
    extern /* Subroutine */ int clacn2_(integer *, complex *, complex *, real 
	    *, integer *, integer *);
    real xnorm;
    extern integer icamax_(integer *, complex *, integer *);
    extern doublereal slamch_(char *);
    extern /* Subroutine */ int xerbla_(char *, integer *);
    extern doublereal clantr_(char *, char *, char *, integer *, integer *, 
	    complex *, integer *, real *);
    real ainvnm;
    extern /* Subroutine */ int clatrs_(char *, char *, char *, char *, 
	    integer *, complex *, integer *, complex *, real *, real *, 
	    integer *), csrscl_(integer *, 
	    real *, complex *, integer *);
    logical onenrm;
    char normin[1];
    real smlnum;
    logical nounit;


/*  -- LAPACK routine (version 3.1) -- */
/*     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 */
/*  ======= */

/*  CTRCON estimates the reciprocal of the condition number of a */
/*  triangular matrix A, in either the 1-norm or the infinity-norm. */

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

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

/*  NORM    (input) CHARACTER*1 */
/*          Specifies whether the 1-norm condition number or the */
/*          infinity-norm condition number is required: */
/*          = '1' or 'O':  1-norm; */
/*          = 'I':         Infinity-norm. */

/*  UPLO    (input) CHARACTER*1 */
/*          = 'U':  A is upper triangular; */
/*          = 'L':  A is lower triangular. */

/*  DIAG    (input) CHARACTER*1 */
/*          = 'N':  A is non-unit triangular; */
/*          = 'U':  A is unit triangular. */

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

/*  A       (input) COMPLEX array, dimension (LDA,N) */
/*          The triangular matrix A.  If UPLO = 'U', the leading N-by-N */
/*          upper triangular part of the array A contains the upper */
/*          triangular matrix, and the strictly lower triangular part of */
/*          A is not referenced.  If UPLO = 'L', the leading N-by-N lower */
/*          triangular part of the array A contains the lower triangular */
/*          matrix, and the strictly upper triangular part of A is not */
/*          referenced.  If DIAG = 'U', the diagonal elements of A are */
/*          also not referenced and are assumed to be 1. */

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

/*  RCOND   (output) REAL */
/*          The reciprocal of the condition number of the matrix A, */
/*          computed as RCOND = 1/(norm(A) * norm(inv(A))). */

/*  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 */

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

/*     .. Parameters .. */
/*     .. */
/*     .. Local Scalars .. */
/*     .. */
/*     .. Local Arrays .. */
/*     .. */
/*     .. External Functions .. */
/*     .. */
/*     .. External Subroutines .. */
/*     .. */
/*     .. Intrinsic 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;
    --work;
    --rwork;

    /* Function Body */
    *info = 0;
    upper = lsame_(uplo, "U");
    onenrm = *(unsigned char *)norm == '1' || lsame_(norm, "O");
    nounit = lsame_(diag, "N");

    if (! onenrm && ! lsame_(norm, "I")) {
	*info = -1;
    } else if (! upper && ! lsame_(uplo, "L")) {
	*info = -2;
    } else if (! nounit && ! lsame_(diag, "U")) {
	*info = -3;
    } else if (*n < 0) {
	*info = -4;
    } else if (*lda < max(1,*n)) {
	*info = -6;
    }
    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("CTRCON", &i__1);
	return 0;
    }

/*     Quick return if possible */

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

    *rcond = 0.f;
    smlnum = slamch_("Safe minimum") * (real) max(1,*n);

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

    anorm = clantr_(norm, uplo, diag, n, n, &a[a_offset], lda, &rwork[1]);

/*     Continue only if ANORM > 0. */

    if (anorm > 0.f) {

/*        Estimate the norm of the inverse of A. */

	ainvnm = 0.f;
	*(unsigned char *)normin = 'N';
	if (onenrm) {
	    kase1 = 1;
	} else {
	    kase1 = 2;
	}
	kase = 0;
L10:
	clacn2_(n, &work[*n + 1], &work[1], &ainvnm, &kase, isave);
	if (kase != 0) {
	    if (kase == kase1) {

/*              Multiply by inv(A). */

		clatrs_(uplo, "No transpose", diag, normin, n, &a[a_offset], 
			lda, &work[1], &scale, &rwork[1], info);
	    } else {

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

		clatrs_(uplo, "Conjugate transpose", diag, normin, n, &a[
			a_offset], lda, &work[1], &scale, &rwork[1], info);
	    }
	    *(unsigned char *)normin = 'Y';

/*           Multiply by 1/SCALE if doing so will not cause overflow. */

	    if (scale != 1.f) {
		ix = icamax_(n, &work[1], &c__1);
		i__1 = ix;
		xnorm = (r__1 = work[i__1].r, dabs(r__1)) + (r__2 = r_imag(&
			work[ix]), dabs(r__2));
		if (scale < xnorm * smlnum || scale == 0.f) {
		    goto L20;
		}
		csrscl_(n, &scale, &work[1], &c__1);
	    }
	    goto L10;
	}

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

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

L20:
    return 0;

/*     End of CTRCON */

} /* ctrcon_ */
Example #2
0
/* Subroutine */
int cgesvx_(char *fact, char *trans, integer *n, integer * nrhs, complex *a, integer *lda, complex *af, integer *ldaf, integer * ipiv, char *equed, real *r__, real *c__, complex *b, integer *ldb, complex *x, integer *ldx, real *rcond, 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;
    complex q__1;
    /* Local variables */
    integer i__, j;
    real amax;
    char norm[1];
    extern logical lsame_(char *, char *);
    real rcmin, rcmax, anorm;
    logical equil;
    extern real clange_(char *, integer *, integer *, complex *, integer *, real *);
    extern /* Subroutine */
    int claqge_(integer *, integer *, complex *, integer *, real *, real *, real *, real *, real *, char *) , cgecon_(char *, integer *, complex *, integer *, real *, real *, complex *, real *, integer *);
    real colcnd;
    extern real slamch_(char *);
    extern /* Subroutine */
    int cgeequ_(integer *, integer *, complex *, integer *, real *, real *, real *, real *, real *, integer *);
    logical nofact;
    extern /* Subroutine */
    int cgerfs_(char *, integer *, integer *, complex *, integer *, complex *, integer *, integer *, complex *, integer *, complex *, integer *, real *, real *, complex *, real *, integer *), cgetrf_(integer *, integer *, complex *, integer *, integer *, integer *), clacpy_(char *, integer *, integer *, complex *, integer *, complex *, integer *), xerbla_(char *, integer *);
    real bignum;
    extern real clantr_(char *, char *, char *, integer *, integer *, complex *, integer *, real *);
    integer infequ;
    logical colequ;
    extern /* Subroutine */
    int cgetrs_(char *, integer *, integer *, complex *, integer *, integer *, complex *, integer *, integer *);
    real rowcnd;
    logical notran;
    real smlnum;
    logical rowequ;
    real rpvgrw;
    /* -- LAPACK driver routine (version 3.4.1) -- */
    /* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
    /* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
    /* April 2012 */
    /* .. Scalar Arguments .. */
    /* .. */
    /* .. Array Arguments .. */
    /* .. */
    /* ===================================================================== */
    /* .. Parameters .. */
    /* .. */
    /* .. Local Scalars .. */
    /* .. */
    /* .. External Functions .. */
    /* .. */
    /* .. External Subroutines .. */
    /* .. */
    /* .. Intrinsic Functions .. */
    /* .. */
    /* .. Executable Statements .. */
    /* Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    af_dim1 = *ldaf;
    af_offset = 1 + af_dim1;
    af -= af_offset;
    --ipiv;
    --r__;
    --c__;
    b_dim1 = *ldb;
    b_offset = 1 + b_dim1;
    b -= b_offset;
    x_dim1 = *ldx;
    x_offset = 1 + x_dim1;
    x -= x_offset;
    --ferr;
    --berr;
    --work;
    --rwork;
    /* Function Body */
    *info = 0;
    nofact = lsame_(fact, "N");
    equil = lsame_(fact, "E");
    notran = lsame_(trans, "N");
    if (nofact || equil)
    {
        *(unsigned char *)equed = 'N';
        rowequ = FALSE_;
        colequ = FALSE_;
    }
    else
    {
        rowequ = lsame_(equed, "R") || lsame_(equed, "B");
        colequ = lsame_(equed, "C") || lsame_(equed, "B");
        smlnum = slamch_("Safe minimum");
        bignum = 1.f / smlnum;
    }
    /* Test the input parameters. */
    if (! nofact && ! equil && ! lsame_(fact, "F"))
    {
        *info = -1;
    }
    else if (! notran && ! lsame_(trans, "T") && ! lsame_(trans, "C"))
    {
        *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 (lsame_(fact, "F") && ! (rowequ || colequ || lsame_(equed, "N")))
    {
        *info = -10;
    }
    else
    {
        if (rowequ)
        {
            rcmin = bignum;
            rcmax = 0.f;
            i__1 = *n;
            for (j = 1;
                    j <= i__1;
                    ++j)
            {
                /* Computing MIN */
                r__1 = rcmin;
                r__2 = r__[j]; // , expr subst
                rcmin = min(r__1,r__2);
                /* Computing MAX */
                r__1 = rcmax;
                r__2 = r__[j]; // , expr subst
                rcmax = max(r__1,r__2);
                /* L10: */
            }
            if (rcmin <= 0.f)
            {
                *info = -11;
            }
            else if (*n > 0)
            {
                rowcnd = max(rcmin,smlnum) / min(rcmax,bignum);
            }
            else
            {
                rowcnd = 1.f;
            }
        }
        if (colequ && *info == 0)
        {
            rcmin = bignum;
            rcmax = 0.f;
            i__1 = *n;
            for (j = 1;
                    j <= i__1;
                    ++j)
            {
                /* Computing MIN */
                r__1 = rcmin;
                r__2 = c__[j]; // , expr subst
                rcmin = min(r__1,r__2);
                /* Computing MAX */
                r__1 = rcmax;
                r__2 = c__[j]; // , expr subst
                rcmax = max(r__1,r__2);
                /* L20: */
            }
            if (rcmin <= 0.f)
            {
                *info = -12;
            }
            else if (*n > 0)
            {
                colcnd = max(rcmin,smlnum) / min(rcmax,bignum);
            }
            else
            {
                colcnd = 1.f;
            }
        }
        if (*info == 0)
        {
            if (*ldb < max(1,*n))
            {
                *info = -14;
            }
            else if (*ldx < max(1,*n))
            {
                *info = -16;
            }
        }
    }
    if (*info != 0)
    {
        i__1 = -(*info);
        xerbla_("CGESVX", &i__1);
        return 0;
    }
    if (equil)
    {
        /* Compute row and column scalings to equilibrate the matrix A. */
        cgeequ_(n, n, &a[a_offset], lda, &r__[1], &c__[1], &rowcnd, &colcnd, & amax, &infequ);
        if (infequ == 0)
        {
            /* Equilibrate the matrix. */
            claqge_(n, n, &a[a_offset], lda, &r__[1], &c__[1], &rowcnd, & colcnd, &amax, equed);
            rowequ = lsame_(equed, "R") || lsame_(equed, "B");
            colequ = lsame_(equed, "C") || lsame_(equed, "B");
        }
    }
    /* Scale the right hand side. */
    if (notran)
    {
        if (rowequ)
        {
            i__1 = *nrhs;
            for (j = 1;
                    j <= i__1;
                    ++j)
            {
                i__2 = *n;
                for (i__ = 1;
                        i__ <= i__2;
                        ++i__)
                {
                    i__3 = i__ + j * b_dim1;
                    i__4 = i__;
                    i__5 = i__ + j * b_dim1;
                    q__1.r = r__[i__4] * b[i__5].r;
                    q__1.i = r__[i__4] * b[ i__5].i; // , expr subst
                    b[i__3].r = q__1.r;
                    b[i__3].i = q__1.i; // , expr subst
                    /* L30: */
                }
                /* L40: */
            }
        }
    }
    else if (colequ)
    {
        i__1 = *nrhs;
        for (j = 1;
                j <= i__1;
                ++j)
        {
            i__2 = *n;
            for (i__ = 1;
                    i__ <= i__2;
                    ++i__)
            {
                i__3 = i__ + j * b_dim1;
                i__4 = i__;
                i__5 = i__ + j * b_dim1;
                q__1.r = c__[i__4] * b[i__5].r;
                q__1.i = c__[i__4] * b[i__5] .i; // , expr subst
                b[i__3].r = q__1.r;
                b[i__3].i = q__1.i; // , expr subst
                /* L50: */
            }
            /* L60: */
        }
    }
    if (nofact || equil)
    {
        /* Compute the LU factorization of A. */
        clacpy_("Full", n, n, &a[a_offset], lda, &af[af_offset], ldaf);
        cgetrf_(n, n, &af[af_offset], ldaf, &ipiv[1], info);
        /* Return if INFO is non-zero. */
        if (*info > 0)
        {
            /* Compute the reciprocal pivot growth factor of the */
            /* leading rank-deficient INFO columns of A. */
            rpvgrw = clantr_("M", "U", "N", info, info, &af[af_offset], ldaf, &rwork[1]);
            if (rpvgrw == 0.f)
            {
                rpvgrw = 1.f;
            }
            else
            {
                rpvgrw = clange_("M", n, info, &a[a_offset], lda, &rwork[1]) / rpvgrw;
            }
            rwork[1] = rpvgrw;
            *rcond = 0.f;
            return 0;
        }
    }
    /* Compute the norm of the matrix A and the */
    /* reciprocal pivot growth factor RPVGRW. */
    if (notran)
    {
        *(unsigned char *)norm = '1';
    }
    else
    {
        *(unsigned char *)norm = 'I';
    }
    anorm = clange_(norm, n, n, &a[a_offset], lda, &rwork[1]);
    rpvgrw = clantr_("M", "U", "N", n, n, &af[af_offset], ldaf, &rwork[1]);
    if (rpvgrw == 0.f)
    {
        rpvgrw = 1.f;
    }
    else
    {
        rpvgrw = clange_("M", n, n, &a[a_offset], lda, &rwork[1]) / rpvgrw;
    }
    /* Compute the reciprocal of the condition number of A. */
    cgecon_(norm, n, &af[af_offset], ldaf, &anorm, rcond, &work[1], &rwork[1], info);
    /* Compute the solution matrix X. */
    clacpy_("Full", n, nrhs, &b[b_offset], ldb, &x[x_offset], ldx);
    cgetrs_(trans, n, nrhs, &af[af_offset], ldaf, &ipiv[1], &x[x_offset], ldx, info);
    /* Use iterative refinement to improve the computed solution and */
    /* compute error bounds and backward error estimates for it. */
    cgerfs_(trans, 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);
    /* Transform the solution matrix X to a solution of the original */
    /* system. */
    if (notran)
    {
        if (colequ)
        {
            i__1 = *nrhs;
            for (j = 1;
                    j <= i__1;
                    ++j)
            {
                i__2 = *n;
                for (i__ = 1;
                        i__ <= i__2;
                        ++i__)
                {
                    i__3 = i__ + j * x_dim1;
                    i__4 = i__;
                    i__5 = i__ + j * x_dim1;
                    q__1.r = c__[i__4] * x[i__5].r;
                    q__1.i = c__[i__4] * x[ i__5].i; // , expr subst
                    x[i__3].r = q__1.r;
                    x[i__3].i = q__1.i; // , expr subst
                    /* L70: */
                }
                /* L80: */
            }
            i__1 = *nrhs;
            for (j = 1;
                    j <= i__1;
                    ++j)
            {
                ferr[j] /= colcnd;
                /* L90: */
            }
        }
    }
    else if (rowequ)
    {
        i__1 = *nrhs;
        for (j = 1;
                j <= i__1;
                ++j)
        {
            i__2 = *n;
            for (i__ = 1;
                    i__ <= i__2;
                    ++i__)
            {
                i__3 = i__ + j * x_dim1;
                i__4 = i__;
                i__5 = i__ + j * x_dim1;
                q__1.r = r__[i__4] * x[i__5].r;
                q__1.i = r__[i__4] * x[i__5] .i; // , expr subst
                x[i__3].r = q__1.r;
                x[i__3].i = q__1.i; // , expr subst
                /* L100: */
            }
            /* L110: */
        }
        i__1 = *nrhs;
        for (j = 1;
                j <= i__1;
                ++j)
        {
            ferr[j] /= rowcnd;
            /* L120: */
        }
    }
    /* Set INFO = N+1 if the matrix is singular to working precision. */
    if (*rcond < slamch_("Epsilon"))
    {
        *info = *n + 1;
    }
    rwork[1] = rpvgrw;
    return 0;
    /* End of CGESVX */
}