Example #1
0
/* Subroutine */ int sgbsvx_(char *fact, char *trans, integer *n, integer *kl, 
	 integer *ku, integer *nrhs, real *ab, integer *ldab, real *afb, 
	integer *ldafb, integer *ipiv, char *equed, real *r__, real *c__, 
	real *b, integer *ldb, real *x, integer *ldx, real *rcond, real *ferr, 
	 real *berr, real *work, integer *iwork, integer *info)
{
    /* System generated locals */
    integer ab_dim1, ab_offset, afb_dim1, afb_offset, b_dim1, b_offset, 
	    x_dim1, x_offset, i__1, i__2, i__3, i__4, i__5;
    real r__1, r__2, r__3;

    /* Local variables */
    integer i__, j, j1, j2;
    real amax;
    char norm[1];
    real rcmin, rcmax, anorm;
    logical equil;
    real colcnd;
    logical nofact;
    real bignum;
    integer infequ;
    logical colequ;
    real rowcnd;
    logical notran;
    real smlnum;
    logical rowequ;
    real rpvgrw;

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

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

/*  SGBSVX uses the LU factorization to compute the solution to a real */
/*  system of linear equations A * X = B, A**T * X = B, or A**H * X = B, */
/*  where A is a band matrix of order N with KL subdiagonals and KU */
/*  superdiagonals, 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 by this subroutine: */

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

/*  2. If FACT = 'N' or 'E', the LU decomposition is used to factor the */
/*     matrix A (after equilibration if FACT = 'E') as */
/*        A = L * U, */
/*     where L is a product of permutation and unit lower triangular */
/*     matrices with KL subdiagonals, and U is upper triangular with */
/*     KL+KU superdiagonals. */

/*  3. If some U(i,i)=0, so that U 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. */

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

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

/*  6. If equilibration was used, the matrix X is premultiplied by */
/*     diag(C) (if TRANS = 'N') or diag(R) (if TRANS = 'T' or 'C') so */
/*     that it solves the original system before equilibration. */

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

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

/*  TRANS   (input) CHARACTER*1 */
/*          Specifies the form of the system of equations. */
/*          = 'N':  A * X = B     (No transpose) */
/*          = 'T':  A**T * X = B  (Transpose) */
/*          = 'C':  A**H * X = B  (Transpose) */

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

/*  KL      (input) INTEGER */
/*          The number of subdiagonals within the band of A.  KL >= 0. */

/*  KU      (input) INTEGER */
/*          The number of superdiagonals within the band of A.  KU >= 0. */

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

/*  AB      (input/output) REAL array, dimension (LDAB,N) */
/*          On entry, the matrix A in band storage, in rows 1 to KL+KU+1. */
/*          The j-th column of A is stored in the j-th column of the */
/*          array AB as follows: */
/*          AB(KU+1+i-j,j) = A(i,j) for max(1,j-KU)<=i<=min(N,j+kl) */

/*          If FACT = 'F' and EQUED is not 'N', then A must have been */
/*          equilibrated by the scaling factors in R and/or C.  AB is not */
/*          modified if FACT = 'F' or 'N', or if FACT = 'E' and */
/*          EQUED = 'N' on exit. */

/*          On exit, if EQUED .ne. 'N', A is scaled as follows: */
/*          EQUED = 'R':  A := diag(R) * A */
/*          EQUED = 'C':  A := A * diag(C) */
/*          EQUED = 'B':  A := diag(R) * A * diag(C). */

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

/*  AFB     (input or output) REAL array, dimension (LDAFB,N) */
/*          If FACT = 'F', then AFB is an input argument and on entry */
/*          contains details of the LU factorization of the band matrix */
/*          A, as computed by SGBTRF.  U is stored as an upper triangular */
/*          band matrix with KL+KU superdiagonals in rows 1 to KL+KU+1, */
/*          and the multipliers used during the factorization are stored */
/*          in rows KL+KU+2 to 2*KL+KU+1.  If EQUED .ne. 'N', then AFB is */
/*          the factored form of the equilibrated matrix A. */

/*          If FACT = 'N', then AFB is an output argument and on exit */
/*          returns details of the LU factorization of A. */

/*          If FACT = 'E', then AFB is an output argument and on exit */
/*          returns details of the LU factorization of the equilibrated */
/*          matrix A (see the description of AB for the form of the */
/*          equilibrated matrix). */

/*  LDAFB   (input) INTEGER */
/*          The leading dimension of the array AFB.  LDAFB >= 2*KL+KU+1. */

/*  IPIV    (input or output) INTEGER array, dimension (N) */
/*          If FACT = 'F', then IPIV is an input argument and on entry */
/*          contains the pivot indices from the factorization A = L*U */
/*          as computed by SGBTRF; row i of the matrix was interchanged */
/*          with row IPIV(i). */

/*          If FACT = 'N', then IPIV is an output argument and on exit */
/*          contains the pivot indices from the factorization A = L*U */
/*          of the original matrix A. */

/*          If FACT = 'E', then IPIV is an output argument and on exit */
/*          contains the pivot indices from the factorization A = L*U */
/*          of the equilibrated matrix A. */

/*  EQUED   (input or output) CHARACTER*1 */
/*          Specifies the form of equilibration that was done. */
/*          = 'N':  No equilibration (always true if FACT = 'N'). */
/*          = 'R':  Row equilibration, i.e., A has been premultiplied by */
/*                  diag(R). */
/*          = 'C':  Column equilibration, i.e., A has been postmultiplied */
/*                  by diag(C). */
/*          = 'B':  Both row and column equilibration, i.e., A has been */
/*                  replaced by diag(R) * A * diag(C). */
/*          EQUED is an input argument if FACT = 'F'; otherwise, it is an */
/*          output argument. */

/*  R       (input or output) REAL array, dimension (N) */
/*          The row scale factors for A.  If EQUED = 'R' or 'B', A is */
/*          multiplied on the left by diag(R); if EQUED = 'N' or 'C', R */
/*          is not accessed.  R is an input argument if FACT = 'F'; */
/*          otherwise, R is an output argument.  If FACT = 'F' and */
/*          EQUED = 'R' or 'B', each element of R must be positive. */

/*  C       (input or output) REAL array, dimension (N) */
/*          The column scale factors for A.  If EQUED = 'C' or 'B', A is */
/*          multiplied on the right by diag(C); if EQUED = 'N' or 'R', C */
/*          is not accessed.  C is an input argument if FACT = 'F'; */
/*          otherwise, C is an output argument.  If FACT = 'F' and */
/*          EQUED = 'C' or 'B', each element of C must be positive. */

/*  B       (input/output) REAL array, dimension (LDB,NRHS) */
/*          On entry, the right hand side matrix B. */
/*          On exit, */
/*          if EQUED = 'N', B is not modified; */
/*          if TRANS = 'N' and EQUED = 'R' or 'B', B is overwritten by */
/*          diag(R)*B; */
/*          if TRANS = 'T' or 'C' and EQUED = 'C' or 'B', B is */
/*          overwritten by diag(C)*B. */

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

/*  X       (output) REAL array, dimension (LDX,NRHS) */
/*          If INFO = 0 or INFO = N+1, the N-by-NRHS solution matrix X */
/*          to the original system of equations.  Note that A and B are */
/*          modified on exit if EQUED .ne. 'N', and the solution to the */
/*          equilibrated system is inv(diag(C))*X if TRANS = 'N' and */
/*          EQUED = 'C' or 'B', or inv(diag(R))*X if TRANS = 'T' or 'C' */
/*          and EQUED = 'R' or 'B'. */

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

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

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

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

/*  WORK    (workspace/output) REAL array, dimension (3*N) */
/*          On exit, WORK(1) contains the reciprocal pivot growth */
/*          factor norm(A)/norm(U). The "max absolute element" norm is */
/*          used. If WORK(1) is much less than 1, then the stability */
/*          of the LU factorization of the (equilibrated) matrix A */
/*          could be poor. This also means that the solution X, condition */
/*          estimator RCOND, and forward error bound FERR could be */
/*          unreliable. If factorization fails with 0<INFO<=N, then */
/*          WORK(1) contains the reciprocal pivot growth factor for the */
/*          leading INFO columns of A. */

/*  IWORK   (workspace) INTEGER 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:  U(i,i) is exactly zero.  The factorization */
/*                       has been completed, but the factor U is exactly */
/*                       singular, so the solution and error bounds */
/*                       could not be computed. RCOND = 0 is returned. */
/*                = N+1: U is nonsingular, but RCOND is less than machine */
/*                       precision, meaning that the matrix is singular */
/*                       to working precision.  Nevertheless, the */
/*                       solution and error bounds are computed because */
/*                       there are a number of situations where the */
/*                       computed solution can be more accurate than the */

/*                       value of RCOND would suggest. */
/*  ===================================================================== */
/*  Moved setting of INFO = N+1 so INFO does not subsequently get */
/*  overwritten.  Sven, 17 Mar 05. */
/*  ===================================================================== */

    /* Parameter adjustments */
    ab_dim1 = *ldab;
    ab_offset = 1 + ab_dim1;
    ab -= ab_offset;
    afb_dim1 = *ldafb;
    afb_offset = 1 + afb_dim1;
    afb -= afb_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;
    --iwork;

    /* 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 (*kl < 0) {
	*info = -4;
    } else if (*ku < 0) {
	*info = -5;
    } else if (*nrhs < 0) {
	*info = -6;
    } else if (*ldab < *kl + *ku + 1) {
	*info = -8;
    } else if (*ldafb < (*kl << 1) + *ku + 1) {
	*info = -10;
    } else if (lsame_(fact, "F") && ! (rowequ || colequ 
	    || lsame_(equed, "N"))) {
	*info = -12;
    } 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];
		rcmin = dmin(r__1,r__2);
/* Computing MAX */
		r__1 = rcmax, r__2 = r__[j];
		rcmax = dmax(r__1,r__2);
	    }
	    if (rcmin <= 0.f) {
		*info = -13;
	    } else if (*n > 0) {
		rowcnd = dmax(rcmin,smlnum) / dmin(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];
		rcmin = dmin(r__1,r__2);
/* Computing MAX */
		r__1 = rcmax, r__2 = c__[j];
		rcmax = dmax(r__1,r__2);
	    }
	    if (rcmin <= 0.f) {
		*info = -14;
	    } else if (*n > 0) {
		colcnd = dmax(rcmin,smlnum) / dmin(rcmax,bignum);
	    } else {
		colcnd = 1.f;
	    }
	}
	if (*info == 0) {
	    if (*ldb < max(1,*n)) {
		*info = -16;
	    } else if (*ldx < max(1,*n)) {
		*info = -18;
	    }
	}
    }

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

    if (equil) {

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

	sgbequ_(n, n, kl, ku, &ab[ab_offset], ldab, &r__[1], &c__[1], &rowcnd, 
		 &colcnd, &amax, &infequ);
	if (infequ == 0) {

/*           Equilibrate the matrix. */

	    slaqgb_(n, n, kl, ku, &ab[ab_offset], ldab, &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__) {
		    b[i__ + j * b_dim1] = r__[i__] * b[i__ + j * b_dim1];
		}
	    }
	}
    } else if (colequ) {
	i__1 = *nrhs;
	for (j = 1; j <= i__1; ++j) {
	    i__2 = *n;
	    for (i__ = 1; i__ <= i__2; ++i__) {
		b[i__ + j * b_dim1] = c__[i__] * b[i__ + j * b_dim1];
	    }
	}
    }

    if (nofact || equil) {

/*        Compute the LU factorization of the band matrix A. */

	i__1 = *n;
	for (j = 1; j <= i__1; ++j) {
/* Computing MAX */
	    i__2 = j - *ku;
	    j1 = max(i__2,1);
/* Computing MIN */
	    i__2 = j + *kl;
	    j2 = min(i__2,*n);
	    i__2 = j2 - j1 + 1;
	    scopy_(&i__2, &ab[*ku + 1 - j + j1 + j * ab_dim1], &c__1, &afb[*
		    kl + *ku + 1 - j + j1 + j * afb_dim1], &c__1);
	}

	sgbtrf_(n, n, kl, ku, &afb[afb_offset], ldafb, &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. */

	    anorm = 0.f;
	    i__1 = *info;
	    for (j = 1; j <= i__1; ++j) {
/* Computing MAX */
		i__2 = *ku + 2 - j;
/* Computing MIN */
		i__4 = *n + *ku + 1 - j, i__5 = *kl + *ku + 1;
		i__3 = min(i__4,i__5);
		for (i__ = max(i__2,1); i__ <= i__3; ++i__) {
/* Computing MAX */
		    r__2 = anorm, r__3 = (r__1 = ab[i__ + j * ab_dim1], dabs(
			    r__1));
		    anorm = dmax(r__2,r__3);
		}
	    }
/* Computing MIN */
	    i__3 = *info - 1, i__2 = *kl + *ku;
	    i__1 = min(i__3,i__2);
/* Computing MAX */
	    i__4 = 1, i__5 = *kl + *ku + 2 - *info;
	    rpvgrw = slantb_("M", "U", "N", info, &i__1, &afb[max(i__4, i__5)
		    + afb_dim1], ldafb, &work[1]);
	    if (rpvgrw == 0.f) {
		rpvgrw = 1.f;
	    } else {
		rpvgrw = anorm / rpvgrw;
	    }
	    work[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 = slangb_(norm, n, kl, ku, &ab[ab_offset], ldab, &work[1]);
    i__1 = *kl + *ku;
    rpvgrw = slantb_("M", "U", "N", n, &i__1, &afb[afb_offset], ldafb, &work[
	    1]);
    if (rpvgrw == 0.f) {
	rpvgrw = 1.f;
    } else {
	rpvgrw = slangb_("M", n, kl, ku, &ab[ab_offset], ldab, &work[1]) / rpvgrw;
    }

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

    sgbcon_(norm, n, kl, ku, &afb[afb_offset], ldafb, &ipiv[1], &anorm, rcond, 
	     &work[1], &iwork[1], info);

/*     Compute the solution matrix X. */

    slacpy_("Full", n, nrhs, &b[b_offset], ldb, &x[x_offset], ldx);
    sgbtrs_(trans, n, kl, ku, nrhs, &afb[afb_offset], ldafb, &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. */

    sgbrfs_(trans, n, kl, ku, nrhs, &ab[ab_offset], ldab, &afb[afb_offset], 
	    ldafb, &ipiv[1], &b[b_offset], ldb, &x[x_offset], ldx, &ferr[1], &
	    berr[1], &work[1], &iwork[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__3 = *n;
		for (i__ = 1; i__ <= i__3; ++i__) {
		    x[i__ + j * x_dim1] = c__[i__] * x[i__ + j * x_dim1];
		}
	    }
	    i__1 = *nrhs;
	    for (j = 1; j <= i__1; ++j) {
		ferr[j] /= colcnd;
	    }
	}
    } else if (rowequ) {
	i__1 = *nrhs;
	for (j = 1; j <= i__1; ++j) {
	    i__3 = *n;
	    for (i__ = 1; i__ <= i__3; ++i__) {
		x[i__ + j * x_dim1] = r__[i__] * x[i__ + j * x_dim1];
	    }
	}
	i__1 = *nrhs;
	for (j = 1; j <= i__1; ++j) {
	    ferr[j] /= rowcnd;
	}
    }

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

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

    work[1] = rpvgrw;
    return 0;

/*     End of SGBSVX */

} /* sgbsvx_ */
Example #2
0
/* Subroutine */ int sdrvgb_(logical *dotype, integer *nn, integer *nval, 
	integer *nrhs, real *thresh, logical *tsterr, real *a, integer *la, 
	real *afb, integer *lafb, real *asav, real *b, real *bsav, real *x, 
	real *xact, real *s, real *work, real *rwork, integer *iwork, integer 
	*nout)
{
    /* Initialized data */

    static integer iseedy[4] = { 1988,1989,1990,1991 };
    static char transs[1*3] = "N" "T" "C";
    static char facts[1*3] = "F" "N" "E";
    static char equeds[1*4] = "N" "R" "C" "B";

    /* Format strings */
    static char fmt_9999[] = "(\002 *** In SDRVGB, LA=\002,i5,\002 is too sm"
	    "all for N=\002,i5,\002, KU=\002,i5,\002, KL=\002,i5,/\002 ==> In"
	    "crease LA to at least \002,i5)";
    static char fmt_9998[] = "(\002 *** In SDRVGB, LAFB=\002,i5,\002 is too "
	    "small for N=\002,i5,\002, KU=\002,i5,\002, KL=\002,i5,/\002 ==> "
	    "Increase LAFB to at least \002,i5)";
    static char fmt_9997[] = "(1x,a,\002, N=\002,i5,\002, KL=\002,i5,\002, K"
	    "U=\002,i5,\002, type \002,i1,\002, test(\002,i1,\002)=\002,g12.5)"
	    ;
    static char fmt_9995[] = "(1x,a,\002( '\002,a1,\002','\002,a1,\002',\002"
	    ",i5,\002,\002,i5,\002,\002,i5,\002,...), EQUED='\002,a1,\002', t"
	    "ype \002,i1,\002, test(\002,i1,\002)=\002,g12.5)";
    static char fmt_9996[] = "(1x,a,\002( '\002,a1,\002','\002,a1,\002',\002"
	    ",i5,\002,\002,i5,\002,\002,i5,\002,...), type \002,i1,\002, test("
	    "\002,i1,\002)=\002,g12.5)";

    /* System generated locals */
    address a__1[2];
    integer i__1, i__2, i__3, i__4, i__5, i__6, i__7, i__8, i__9, i__10, 
	    i__11[2];
    real r__1, r__2, r__3;
    char ch__1[2];

    /* Local variables */
    integer i__, j, k, n, i1, i2, k1, nb, in, kl, ku, nt, lda, ldb, ikl, nkl, 
	    iku, nku;
    char fact[1];
    integer ioff, mode;
    real amax;
    char path[3];
    integer imat, info;
    char dist[1], type__[1];
    integer nrun, ldafb, ifact, nfail, iseed[4], nfact;
    char equed[1];
    integer nbmin;
    real rcond, roldc;
    integer nimat;
    real roldi;
    real anorm;
    integer itran;
    logical equil;
    real roldo;
    char trans[1];
    integer izero, nerrs;
    logical zerot;
    char xtype[1];
    logical prefac;
    real colcnd;
    real rcondc;
    logical nofact;
    integer iequed;
    real rcondi;
    real cndnum, anormi, rcondo, ainvnm;
    logical trfcon;
    real anormo, rowcnd;
    real anrmpv;
    real result[7], rpvgrw;

    /* Fortran I/O blocks */
    static cilist io___26 = { 0, 0, 0, fmt_9999, 0 };
    static cilist io___27 = { 0, 0, 0, fmt_9998, 0 };
    static cilist io___65 = { 0, 0, 0, fmt_9997, 0 };
    static cilist io___72 = { 0, 0, 0, fmt_9995, 0 };
    static cilist io___73 = { 0, 0, 0, fmt_9996, 0 };
    static cilist io___74 = { 0, 0, 0, fmt_9995, 0 };
    static cilist io___75 = { 0, 0, 0, fmt_9996, 0 };
    static cilist io___76 = { 0, 0, 0, fmt_9995, 0 };
    static cilist io___77 = { 0, 0, 0, fmt_9996, 0 };
    static cilist io___78 = { 0, 0, 0, fmt_9995, 0 };
    static cilist io___79 = { 0, 0, 0, fmt_9996, 0 };



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

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

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

/*  SDRVGB tests the driver routines SGBSV and -SVX. */

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

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

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

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

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

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

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

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

/*  LA      (input) INTEGER */
/*          The length of the array A.  LA >= (2*NMAX-1)*NMAX */
/*          where NMAX is the largest entry in NVAL. */

/*  AFB     (workspace) REAL array, dimension (LAFB) */

/*  LAFB    (input) INTEGER */
/*          The length of the array AFB.  LAFB >= (3*NMAX-2)*NMAX */
/*          where NMAX is the largest entry in NVAL. */

/*  ASAV    (workspace) REAL array, dimension (LA) */

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

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

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

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

/*  S       (workspace) REAL array, dimension (2*NMAX) */

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

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

/*  IWORK   (workspace) INTEGER array, dimension (2*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;
    --s;
    --xact;
    --x;
    --bsav;
    --b;
    --asav;
    --afb;
    --a;
    --nval;
    --dotype;

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

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

    s_copy(path, "Single precision", (ftnlen)1, (ftnlen)16);
    s_copy(path + 1, "GB", (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) {
	serrvx_(path, nout);
    }
    infoc_1.infot = 0;

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

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

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

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

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

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

	i__2 = nkl;
	for (ikl = 1; ikl <= i__2; ++ikl) {

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

	    if (ikl == 1) {
		kl = 0;
	    } else if (ikl == 2) {
/* Computing MAX */
		i__3 = n - 1;
		kl = max(i__3,0);
	    } else if (ikl == 3) {
		kl = (n * 3 - 1) / 4;
	    } else if (ikl == 4) {
		kl = (n + 1) / 4;
	    }
	    i__3 = nku;
	    for (iku = 1; iku <= i__3; ++iku) {

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

		if (iku == 1) {
		    ku = 0;
		} else if (iku == 2) {
/* Computing MAX */
		    i__4 = n - 1;
		    ku = max(i__4,0);
		} else if (iku == 3) {
		    ku = (n * 3 - 1) / 4;
		} else if (iku == 4) {
		    ku = (n + 1) / 4;
		}

/*              Check that A and AFB are big enough to generate this */
/*              matrix. */

		lda = kl + ku + 1;
		ldafb = (kl << 1) + ku + 1;
		if (lda * n > *la || ldafb * n > *lafb) {
		    if (nfail == 0 && nerrs == 0) {
			aladhd_(nout, path);
		    }
		    if (lda * n > *la) {
			io___26.ciunit = *nout;
			s_wsfe(&io___26);
			do_fio(&c__1, (char *)&(*la), (ftnlen)sizeof(integer))
				;
			do_fio(&c__1, (char *)&n, (ftnlen)sizeof(integer));
			do_fio(&c__1, (char *)&kl, (ftnlen)sizeof(integer));
			do_fio(&c__1, (char *)&ku, (ftnlen)sizeof(integer));
			i__4 = n * (kl + ku + 1);
			do_fio(&c__1, (char *)&i__4, (ftnlen)sizeof(integer));
			e_wsfe();
			++nerrs;
		    }
		    if (ldafb * n > *lafb) {
			io___27.ciunit = *nout;
			s_wsfe(&io___27);
			do_fio(&c__1, (char *)&(*lafb), (ftnlen)sizeof(
				integer));
			do_fio(&c__1, (char *)&n, (ftnlen)sizeof(integer));
			do_fio(&c__1, (char *)&kl, (ftnlen)sizeof(integer));
			do_fio(&c__1, (char *)&ku, (ftnlen)sizeof(integer));
			i__4 = n * ((kl << 1) + ku + 1);
			do_fio(&c__1, (char *)&i__4, (ftnlen)sizeof(integer));
			e_wsfe();
			++nerrs;
		    }
		    goto L130;
		}

		i__4 = nimat;
		for (imat = 1; imat <= i__4; ++imat) {

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

		    if (! dotype[imat]) {
			goto L120;
		    }

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

		    zerot = imat >= 2 && imat <= 4;
		    if (zerot && n < imat - 1) {
			goto L120;
		    }

/*                 Set up parameters with SLATB4 and generate a */
/*                 test matrix with SLATMS. */

		    slatb4_(path, &imat, &n, &n, type__, &kl, &ku, &anorm, &
			    mode, &cndnum, dist);
		    rcondc = 1.f / cndnum;

		    s_copy(srnamc_1.srnamt, "SLATMS", (ftnlen)32, (ftnlen)6);
		    slatms_(&n, &n, dist, iseed, type__, &rwork[1], &mode, &
			    cndnum, &anorm, &kl, &ku, "Z", &a[1], &lda, &work[
			    1], &info);

/*                 Check the error code from SLATMS. */

		    if (info != 0) {
			alaerh_(path, "SLATMS", &info, &c__0, " ", &n, &n, &
				kl, &ku, &c_n1, &imat, &nfail, &nerrs, nout);
			goto L120;
		    }

/*                 For types 2, 3, and 4, zero one or more columns of */
/*                 the matrix to test that INFO is returned correctly. */

		    izero = 0;
		    if (zerot) {
			if (imat == 2) {
			    izero = 1;
			} else if (imat == 3) {
			    izero = n;
			} else {
			    izero = n / 2 + 1;
			}
			ioff = (izero - 1) * lda;
			if (imat < 4) {
/* Computing MAX */
			    i__5 = 1, i__6 = ku + 2 - izero;
			    i1 = max(i__5,i__6);
/* Computing MIN */
			    i__5 = kl + ku + 1, i__6 = ku + 1 + (n - izero);
			    i2 = min(i__5,i__6);
			    i__5 = i2;
			    for (i__ = i1; i__ <= i__5; ++i__) {
				a[ioff + i__] = 0.f;
/* L20: */
			    }
			} else {
			    i__5 = n;
			    for (j = izero; j <= i__5; ++j) {
/* Computing MAX */
				i__6 = 1, i__7 = ku + 2 - j;
/* Computing MIN */
				i__9 = kl + ku + 1, i__10 = ku + 1 + (n - j);
				i__8 = min(i__9,i__10);
				for (i__ = max(i__6,i__7); i__ <= i__8; ++i__)
					 {
				    a[ioff + i__] = 0.f;
/* L30: */
				}
				ioff += lda;
/* L40: */
			    }
			}
		    }

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

		    i__5 = kl + ku + 1;
		    slacpy_("Full", &i__5, &n, &a[1], &lda, &asav[1], &lda);

		    for (iequed = 1; iequed <= 4; ++iequed) {
			*(unsigned char *)equed = *(unsigned char *)&equeds[
				iequed - 1];
			if (iequed == 1) {
			    nfact = 3;
			} else {
			    nfact = 1;
			}

			i__5 = nfact;
			for (ifact = 1; ifact <= i__5; ++ifact) {
			    *(unsigned char *)fact = *(unsigned char *)&facts[
				    ifact - 1];
			    prefac = lsame_(fact, "F");
			    nofact = lsame_(fact, "N");
			    equil = lsame_(fact, "E");

			    if (zerot) {
				if (prefac) {
				    goto L100;
				}
				rcondo = 0.f;
				rcondi = 0.f;

			    } else if (! nofact) {

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

				i__8 = kl + ku + 1;
				slacpy_("Full", &i__8, &n, &asav[1], &lda, &
					afb[kl + 1], &ldafb);
				if (equil || iequed > 1) {

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

				    sgbequ_(&n, &n, &kl, &ku, &afb[kl + 1], &
					    ldafb, &s[1], &s[n + 1], &rowcnd, 
					    &colcnd, &amax, &info);
				    if (info == 0 && n > 0) {
					if (lsame_(equed, "R")) {
					    rowcnd = 0.f;
					    colcnd = 1.f;
					} else if (lsame_(equed, "C")) {
					    rowcnd = 1.f;
					    colcnd = 0.f;
					} else if (lsame_(equed, "B")) {
					    rowcnd = 0.f;
					    colcnd = 0.f;
					}

/*                                Equilibrate the matrix. */

					slaqgb_(&n, &n, &kl, &ku, &afb[kl + 1]
, &ldafb, &s[1], &s[n + 1], &
						rowcnd, &colcnd, &amax, equed);
				    }
				}

/*                          Save the condition number of the */
/*                          non-equilibrated system for use in SGET04. */

				if (equil) {
				    roldo = rcondo;
				    roldi = rcondi;
				}

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

				anormo = slangb_("1", &n, &kl, &ku, &afb[kl + 
					1], &ldafb, &rwork[1]);
				anormi = slangb_("I", &n, &kl, &ku, &afb[kl + 
					1], &ldafb, &rwork[1]);

/*                          Factor the matrix A. */

				sgbtrf_(&n, &n, &kl, &ku, &afb[1], &ldafb, &
					iwork[1], &info);

/*                          Form the inverse of A. */

				slaset_("Full", &n, &n, &c_b48, &c_b49, &work[
					1], &ldb);
				s_copy(srnamc_1.srnamt, "SGBTRS", (ftnlen)32, 
					(ftnlen)6);
				sgbtrs_("No transpose", &n, &kl, &ku, &n, &
					afb[1], &ldafb, &iwork[1], &work[1], &
					ldb, &info);

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

				ainvnm = slange_("1", &n, &n, &work[1], &ldb, 
					&rwork[1]);
				if (anormo <= 0.f || ainvnm <= 0.f) {
				    rcondo = 1.f;
				} else {
				    rcondo = 1.f / anormo / ainvnm;
				}

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

				ainvnm = slange_("I", &n, &n, &work[1], &ldb, 
					&rwork[1]);
				if (anormi <= 0.f || ainvnm <= 0.f) {
				    rcondi = 1.f;
				} else {
				    rcondi = 1.f / anormi / ainvnm;
				}
			    }

			    for (itran = 1; itran <= 3; ++itran) {

/*                          Do for each value of TRANS. */

				*(unsigned char *)trans = *(unsigned char *)&
					transs[itran - 1];
				if (itran == 1) {
				    rcondc = rcondo;
				} else {
				    rcondc = rcondi;
				}

/*                          Restore the matrix A. */

				i__8 = kl + ku + 1;
				slacpy_("Full", &i__8, &n, &asav[1], &lda, &a[
					1], &lda);

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

				s_copy(srnamc_1.srnamt, "SLARHS", (ftnlen)32, 
					(ftnlen)6);
				slarhs_(path, xtype, "Full", trans, &n, &n, &
					kl, &ku, nrhs, &a[1], &lda, &xact[1], 
					&ldb, &b[1], &ldb, iseed, &info);
				*(unsigned char *)xtype = 'C';
				slacpy_("Full", &n, nrhs, &b[1], &ldb, &bsav[
					1], &ldb);

				if (nofact && itran == 1) {

/*                             --- Test SGBSV  --- */

/*                             Compute the LU factorization of the matrix */
/*                             and solve the system. */

				    i__8 = kl + ku + 1;
				    slacpy_("Full", &i__8, &n, &a[1], &lda, &
					    afb[kl + 1], &ldafb);
				    slacpy_("Full", &n, nrhs, &b[1], &ldb, &x[
					    1], &ldb);

				    s_copy(srnamc_1.srnamt, "SGBSV ", (ftnlen)
					    32, (ftnlen)6);
				    sgbsv_(&n, &kl, &ku, nrhs, &afb[1], &
					    ldafb, &iwork[1], &x[1], &ldb, &
					    info);

/*                             Check error code from SGBSV . */

				    if (info != izero) {
					alaerh_(path, "SGBSV ", &info, &izero, 
						 " ", &n, &n, &kl, &ku, nrhs, 
						&imat, &nfail, &nerrs, nout);
				    }

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

				    sgbt01_(&n, &n, &kl, &ku, &a[1], &lda, &
					    afb[1], &ldafb, &iwork[1], &work[
					    1], result);
				    nt = 1;
				    if (izero == 0) {

/*                                Compute residual of the computed */
/*                                solution. */

					slacpy_("Full", &n, nrhs, &b[1], &ldb, 
						 &work[1], &ldb);
					sgbt02_("No transpose", &n, &n, &kl, &
						ku, nrhs, &a[1], &lda, &x[1], 
						&ldb, &work[1], &ldb, &result[
						1]);

/*                                Check solution from generated exact */
/*                                solution. */

					sget04_(&n, nrhs, &x[1], &ldb, &xact[
						1], &ldb, &rcondc, &result[2])
						;
					nt = 3;
				    }

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

				    i__8 = nt;
				    for (k = 1; k <= i__8; ++k) {
					if (result[k - 1] >= *thresh) {
					    if (nfail == 0 && nerrs == 0) {
			  aladhd_(nout, path);
					    }
					    io___65.ciunit = *nout;
					    s_wsfe(&io___65);
					    do_fio(&c__1, "SGBSV ", (ftnlen)6)
						    ;
					    do_fio(&c__1, (char *)&n, (ftnlen)
						    sizeof(integer));
					    do_fio(&c__1, (char *)&kl, (
						    ftnlen)sizeof(integer));
					    do_fio(&c__1, (char *)&ku, (
						    ftnlen)sizeof(integer));
					    do_fio(&c__1, (char *)&imat, (
						    ftnlen)sizeof(integer));
					    do_fio(&c__1, (char *)&k, (ftnlen)
						    sizeof(integer));
					    do_fio(&c__1, (char *)&result[k - 
						    1], (ftnlen)sizeof(real));
					    e_wsfe();
					    ++nfail;
					}
/* L50: */
				    }
				    nrun += nt;
				}

/*                          --- Test SGBSVX --- */

				if (! prefac) {
				    i__8 = (kl << 1) + ku + 1;
				    slaset_("Full", &i__8, &n, &c_b48, &c_b48, 
					     &afb[1], &ldafb);
				}
				slaset_("Full", &n, nrhs, &c_b48, &c_b48, &x[
					1], &ldb);
				if (iequed > 1 && n > 0) {

/*                             Equilibrate the matrix if FACT = 'F' and */
/*                             EQUED = 'R', 'C', or 'B'. */

				    slaqgb_(&n, &n, &kl, &ku, &a[1], &lda, &s[
					    1], &s[n + 1], &rowcnd, &colcnd, &
					    amax, equed);
				}

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

				s_copy(srnamc_1.srnamt, "SGBSVX", (ftnlen)32, 
					(ftnlen)6);
				sgbsvx_(fact, trans, &n, &kl, &ku, nrhs, &a[1]
, &lda, &afb[1], &ldafb, &iwork[1], 
					equed, &s[1], &s[n + 1], &b[1], &ldb, 
					&x[1], &ldb, &rcond, &rwork[1], &
					rwork[*nrhs + 1], &work[1], &iwork[n 
					+ 1], &info);

/*                          Check the error code from SGBSVX. */

				if (info != izero) {
/* Writing concatenation */
				    i__11[0] = 1, a__1[0] = fact;
				    i__11[1] = 1, a__1[1] = trans;
				    s_cat(ch__1, a__1, i__11, &c__2, (ftnlen)
					    2);
				    alaerh_(path, "SGBSVX", &info, &izero, 
					    ch__1, &n, &n, &kl, &ku, nrhs, &
					    imat, &nfail, &nerrs, nout);
				}

/*                          Compare WORK(1) from SGBSVX with the computed */
/*                          reciprocal pivot growth factor RPVGRW */

				if (info != 0) {
				    anrmpv = 0.f;
				    i__8 = info;
				    for (j = 1; j <= i__8; ++j) {
/* Computing MAX */
					i__6 = ku + 2 - j;
/* Computing MIN */
					i__9 = n + ku + 1 - j, i__10 = kl + 
						ku + 1;
					i__7 = min(i__9,i__10);
					for (i__ = max(i__6,1); i__ <= i__7; 
						++i__) {
/* Computing MAX */
					    r__2 = anrmpv, r__3 = (r__1 = a[
						    i__ + (j - 1) * lda], 
						    dabs(r__1));
					    anrmpv = dmax(r__2,r__3);
/* L60: */
					}
/* L70: */
				    }
/* Computing MIN */
				    i__7 = info - 1, i__6 = kl + ku;
				    i__8 = min(i__7,i__6);
/* Computing MAX */
				    i__9 = 1, i__10 = kl + ku + 2 - info;
				    rpvgrw = slantb_("M", "U", "N", &info, &
					    i__8, &afb[max(i__9, i__10)], &
					    ldafb, &work[1]);
				    if (rpvgrw == 0.f) {
					rpvgrw = 1.f;
				    } else {
					rpvgrw = anrmpv / rpvgrw;
				    }
				} else {
				    i__8 = kl + ku;
				    rpvgrw = slantb_("M", "U", "N", &n, &i__8, 
					     &afb[1], &ldafb, &work[1]);
				    if (rpvgrw == 0.f) {
					rpvgrw = 1.f;
				    } else {
					rpvgrw = slangb_("M", &n, &kl, &ku, &
						a[1], &lda, &work[1]) / rpvgrw;
				    }
				}
				result[6] = (r__1 = rpvgrw - work[1], dabs(
					r__1)) / dmax(work[1],rpvgrw) / 
					slamch_("E");

				if (! prefac) {

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

				    sgbt01_(&n, &n, &kl, &ku, &a[1], &lda, &
					    afb[1], &ldafb, &iwork[1], &work[
					    1], result);
				    k1 = 1;
				} else {
				    k1 = 2;
				}

				if (info == 0) {
				    trfcon = FALSE_;

/*                             Compute residual of the computed solution. */

				    slacpy_("Full", &n, nrhs, &bsav[1], &ldb, 
					    &work[1], &ldb);
				    sgbt02_(trans, &n, &n, &kl, &ku, nrhs, &
					    asav[1], &lda, &x[1], &ldb, &work[
					    1], &ldb, &result[1]);

/*                             Check solution from generated exact */
/*                             solution. */

				    if (nofact || prefac && lsame_(equed, 
					    "N")) {
					sget04_(&n, nrhs, &x[1], &ldb, &xact[
						1], &ldb, &rcondc, &result[2])
						;
				    } else {
					if (itran == 1) {
					    roldc = roldo;
					} else {
					    roldc = roldi;
					}
					sget04_(&n, nrhs, &x[1], &ldb, &xact[
						1], &ldb, &roldc, &result[2]);
				    }

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

				    sgbt05_(trans, &n, &kl, &ku, nrhs, &asav[
					    1], &lda, &b[1], &ldb, &x[1], &
					    ldb, &xact[1], &ldb, &rwork[1], &
					    rwork[*nrhs + 1], &result[3]);
				} else {
				    trfcon = TRUE_;
				}

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

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

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

				if (! trfcon) {
				    for (k = k1; k <= 7; ++k) {
					if (result[k - 1] >= *thresh) {
					    if (nfail == 0 && nerrs == 0) {
			  aladhd_(nout, path);
					    }
					    if (prefac) {
			  io___72.ciunit = *nout;
			  s_wsfe(&io___72);
			  do_fio(&c__1, "SGBSVX", (ftnlen)6);
			  do_fio(&c__1, fact, (ftnlen)1);
			  do_fio(&c__1, trans, (ftnlen)1);
			  do_fio(&c__1, (char *)&n, (ftnlen)sizeof(integer));
			  do_fio(&c__1, (char *)&kl, (ftnlen)sizeof(integer));
			  do_fio(&c__1, (char *)&ku, (ftnlen)sizeof(integer));
			  do_fio(&c__1, equed, (ftnlen)1);
			  do_fio(&c__1, (char *)&imat, (ftnlen)sizeof(integer)
				  );
			  do_fio(&c__1, (char *)&k, (ftnlen)sizeof(integer));
			  do_fio(&c__1, (char *)&result[k - 1], (ftnlen)
				  sizeof(real));
			  e_wsfe();
					    } else {
			  io___73.ciunit = *nout;
			  s_wsfe(&io___73);
			  do_fio(&c__1, "SGBSVX", (ftnlen)6);
			  do_fio(&c__1, fact, (ftnlen)1);
			  do_fio(&c__1, trans, (ftnlen)1);
			  do_fio(&c__1, (char *)&n, (ftnlen)sizeof(integer));
			  do_fio(&c__1, (char *)&kl, (ftnlen)sizeof(integer));
			  do_fio(&c__1, (char *)&ku, (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;
					}
/* L80: */
				    }
				    nrun = nrun + 7 - k1;
				} else {
				    if (result[0] >= *thresh && ! prefac) {
					if (nfail == 0 && nerrs == 0) {
					    aladhd_(nout, path);
					}
					if (prefac) {
					    io___74.ciunit = *nout;
					    s_wsfe(&io___74);
					    do_fio(&c__1, "SGBSVX", (ftnlen)6)
						    ;
					    do_fio(&c__1, fact, (ftnlen)1);
					    do_fio(&c__1, trans, (ftnlen)1);
					    do_fio(&c__1, (char *)&n, (ftnlen)
						    sizeof(integer));
					    do_fio(&c__1, (char *)&kl, (
						    ftnlen)sizeof(integer));
					    do_fio(&c__1, (char *)&ku, (
						    ftnlen)sizeof(integer));
					    do_fio(&c__1, equed, (ftnlen)1);
					    do_fio(&c__1, (char *)&imat, (
						    ftnlen)sizeof(integer));
					    do_fio(&c__1, (char *)&c__1, (
						    ftnlen)sizeof(integer));
					    do_fio(&c__1, (char *)&result[0], 
						    (ftnlen)sizeof(real));
					    e_wsfe();
					} else {
					    io___75.ciunit = *nout;
					    s_wsfe(&io___75);
					    do_fio(&c__1, "SGBSVX", (ftnlen)6)
						    ;
					    do_fio(&c__1, fact, (ftnlen)1);
					    do_fio(&c__1, trans, (ftnlen)1);
					    do_fio(&c__1, (char *)&n, (ftnlen)
						    sizeof(integer));
					    do_fio(&c__1, (char *)&kl, (
						    ftnlen)sizeof(integer));
					    do_fio(&c__1, (char *)&ku, (
						    ftnlen)sizeof(integer));
					    do_fio(&c__1, (char *)&imat, (
						    ftnlen)sizeof(integer));
					    do_fio(&c__1, (char *)&c__1, (
						    ftnlen)sizeof(integer));
					    do_fio(&c__1, (char *)&result[0], 
						    (ftnlen)sizeof(real));
					    e_wsfe();
					}
					++nfail;
					++nrun;
				    }
				    if (result[5] >= *thresh) {
					if (nfail == 0 && nerrs == 0) {
					    aladhd_(nout, path);
					}
					if (prefac) {
					    io___76.ciunit = *nout;
					    s_wsfe(&io___76);
					    do_fio(&c__1, "SGBSVX", (ftnlen)6)
						    ;
					    do_fio(&c__1, fact, (ftnlen)1);
					    do_fio(&c__1, trans, (ftnlen)1);
					    do_fio(&c__1, (char *)&n, (ftnlen)
						    sizeof(integer));
					    do_fio(&c__1, (char *)&kl, (
						    ftnlen)sizeof(integer));
					    do_fio(&c__1, (char *)&ku, (
						    ftnlen)sizeof(integer));
					    do_fio(&c__1, equed, (ftnlen)1);
					    do_fio(&c__1, (char *)&imat, (
						    ftnlen)sizeof(integer));
					    do_fio(&c__1, (char *)&c__6, (
						    ftnlen)sizeof(integer));
					    do_fio(&c__1, (char *)&result[5], 
						    (ftnlen)sizeof(real));
					    e_wsfe();
					} else {
					    io___77.ciunit = *nout;
					    s_wsfe(&io___77);
					    do_fio(&c__1, "SGBSVX", (ftnlen)6)
						    ;
					    do_fio(&c__1, fact, (ftnlen)1);
					    do_fio(&c__1, trans, (ftnlen)1);
					    do_fio(&c__1, (char *)&n, (ftnlen)
						    sizeof(integer));
					    do_fio(&c__1, (char *)&kl, (
						    ftnlen)sizeof(integer));
					    do_fio(&c__1, (char *)&ku, (
						    ftnlen)sizeof(integer));
					    do_fio(&c__1, (char *)&imat, (
						    ftnlen)sizeof(integer));
					    do_fio(&c__1, (char *)&c__6, (
						    ftnlen)sizeof(integer));
					    do_fio(&c__1, (char *)&result[5], 
						    (ftnlen)sizeof(real));
					    e_wsfe();
					}
					++nfail;
					++nrun;
				    }
				    if (result[6] >= *thresh) {
					if (nfail == 0 && nerrs == 0) {
					    aladhd_(nout, path);
					}
					if (prefac) {
					    io___78.ciunit = *nout;
					    s_wsfe(&io___78);
					    do_fio(&c__1, "SGBSVX", (ftnlen)6)
						    ;
					    do_fio(&c__1, fact, (ftnlen)1);
					    do_fio(&c__1, trans, (ftnlen)1);
					    do_fio(&c__1, (char *)&n, (ftnlen)
						    sizeof(integer));
					    do_fio(&c__1, (char *)&kl, (
						    ftnlen)sizeof(integer));
					    do_fio(&c__1, (char *)&ku, (
						    ftnlen)sizeof(integer));
					    do_fio(&c__1, equed, (ftnlen)1);
					    do_fio(&c__1, (char *)&imat, (
						    ftnlen)sizeof(integer));
					    do_fio(&c__1, (char *)&c__7, (
						    ftnlen)sizeof(integer));
					    do_fio(&c__1, (char *)&result[6], 
						    (ftnlen)sizeof(real));
					    e_wsfe();
					} else {
					    io___79.ciunit = *nout;
					    s_wsfe(&io___79);
					    do_fio(&c__1, "SGBSVX", (ftnlen)6)
						    ;
					    do_fio(&c__1, fact, (ftnlen)1);
					    do_fio(&c__1, trans, (ftnlen)1);
					    do_fio(&c__1, (char *)&n, (ftnlen)
						    sizeof(integer));
					    do_fio(&c__1, (char *)&kl, (
						    ftnlen)sizeof(integer));
					    do_fio(&c__1, (char *)&ku, (
						    ftnlen)sizeof(integer));
					    do_fio(&c__1, (char *)&imat, (
						    ftnlen)sizeof(integer));
					    do_fio(&c__1, (char *)&c__7, (
						    ftnlen)sizeof(integer));
					    do_fio(&c__1, (char *)&result[6], 
						    (ftnlen)sizeof(real));
					    e_wsfe();
					}
					++nfail;
					++nrun;
				    }

				}
/* L90: */
			    }
L100:
			    ;
			}
/* L110: */
		    }
L120:
		    ;
		}
L130:
		;
	    }
/* L140: */
	}
/* L150: */
    }

/*     Print a summary of the results. */

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


    return 0;

/*     End of SDRVGB */

} /* sdrvgb_ */
Example #3
0
/* Subroutine */ int schkgb_(logical *dotype, integer *nm, integer *mval, 
	integer *nn, integer *nval, integer *nnb, integer *nbval, integer *
	nns, integer *nsval, real *thresh, logical *tsterr, real *a, integer *
	la, real *afac, integer *lafac, real *b, real *x, real *xact, real *
	work, real *rwork, integer *iwork, integer *nout)
{
    /* Initialized data */

    static integer iseedy[4] = { 1988,1989,1990,1991 };
    static char transs[1*3] = "N" "T" "C";

    /* Format strings */
    static char fmt_9999[] = "(\002 *** In SCHKGB, LA=\002,i5,\002 is too sm"
	    "all for M=\002,i5,\002, N=\002,i5,\002, KL=\002,i4,\002, KU=\002"
	    ",i4,/\002 ==> Increase LA to at least \002,i5)";
    static char fmt_9998[] = "(\002 *** In SCHKGB, LAFAC=\002,i5,\002 is too"
	    " small for M=\002,i5,\002, N=\002,i5,\002, KL=\002,i4,\002, KU"
	    "=\002,i4,/\002 ==> Increase LAFAC to at least \002,i5)";
    static char fmt_9997[] = "(\002 M =\002,i5,\002, N =\002,i5,\002, KL="
	    "\002,i5,\002, KU=\002,i5,\002, NB =\002,i4,\002, type \002,i1"
	    ",\002, test(\002,i1,\002)=\002,g12.5)";
    static char fmt_9996[] = "(\002 TRANS='\002,a1,\002', N=\002,i5,\002, "
	    "KL=\002,i5,\002, KU=\002,i5,\002, NRHS=\002,i3,\002, type \002,i"
	    "1,\002, test(\002,i1,\002)=\002,g12.5)";
    static char fmt_9995[] = "(\002 NORM ='\002,a1,\002', N=\002,i5,\002, "
	    "KL=\002,i5,\002, KU=\002,i5,\002,\002,10x,\002 type \002,i1,\002"
	    ", test(\002,i1,\002)=\002,g12.5)";

    /* System generated locals */
    integer i__1, i__2, i__3, i__4, i__5, i__6, i__7, i__8, i__9, i__10, 
	    i__11;

    /* 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, m, n, i1, i2, nb, im, in, kl, ku, lda, ldb, inb, ikl, 
	    nkl, iku, nku, ioff, mode, koff, imat, info;
    char path[3], dist[1];
    integer irhs, nrhs;
    char norm[1], type__[1];
    integer nrun;
    extern /* Subroutine */ int alahd_(integer *, char *);
    integer nfail, iseed[4];
    extern /* Subroutine */ int sgbt01_(integer *, integer *, integer *, 
	    integer *, real *, integer *, real *, integer *, integer *, real *
, real *), sgbt02_(char *, integer *, integer *, integer *, 
	    integer *, integer *, real *, integer *, real *, integer *, real *
, integer *, real *), sgbt05_(char *, integer *, integer *
, integer *, integer *, real *, integer *, real *, integer *, 
	    real *, integer *, real *, integer *, real *, real *, real *);
    real rcond;
    extern /* Subroutine */ int sget04_(integer *, integer *, real *, integer 
	    *, real *, integer *, real *, real *);
    integer nimat, klval[4];
    extern doublereal sget06_(real *, real *);
    real anorm;
    integer itran, kuval[4];
    char trans[1];
    integer izero, nerrs;
    extern /* Subroutine */ int scopy_(integer *, real *, integer *, real *, 
	    integer *);
    logical zerot;
    char xtype[1];
    extern /* Subroutine */ int slatb4_(char *, integer *, integer *, integer 
	    *, char *, integer *, integer *, real *, integer *, real *, char *
);
    integer ldafac;
    extern /* Subroutine */ int alaerh_(char *, char *, integer *, integer *, 
	    char *, integer *, integer *, integer *, integer *, integer *, 
	    integer *, integer *, integer *, integer *);
    extern doublereal slangb_(char *, integer *, integer *, integer *, real *, 
	     integer *, real *);
    real rcondc;
    extern doublereal slange_(char *, integer *, integer *, real *, integer *, 
	     real *);
    extern /* Subroutine */ int sgbcon_(char *, integer *, integer *, integer 
	    *, real *, integer *, integer *, real *, real *, real *, integer *
, integer *);
    real rcondi;
    extern /* Subroutine */ int alasum_(char *, integer *, integer *, integer 
	    *, integer *);
    real cndnum, anormi, rcondo;
    extern /* Subroutine */ int serrge_(char *, integer *);
    real ainvnm;
    extern /* Subroutine */ int sgbrfs_(char *, integer *, integer *, integer 
	    *, integer *, real *, integer *, real *, integer *, integer *, 
	    real *, integer *, real *, integer *, real *, real *, real *, 
	    integer *, integer *), sgbtrf_(integer *, integer *, 
	    integer *, integer *, real *, integer *, integer *, integer *);
    logical trfcon;
    real anormo;
    extern /* Subroutine */ int slacpy_(char *, integer *, integer *, real *, 
	    integer *, real *, integer *), slarhs_(char *, char *, 
	    char *, char *, integer *, integer *, integer *, integer *, 
	    integer *, real *, integer *, real *, integer *, real *, integer *
, integer *, integer *), slaset_(
	    char *, integer *, integer *, real *, real *, real *, integer *), xlaenv_(integer *, integer *), slatms_(integer *, 
	    integer *, char *, integer *, char *, real *, integer *, real *, 
	    real *, integer *, integer *, char *, real *, integer *, real *, 
	    integer *), sgbtrs_(char *, integer *, 
	    integer *, integer *, integer *, real *, integer *, integer *, 
	    real *, integer *, integer *);
    real result[7];

    /* Fortran I/O blocks */
    static cilist io___25 = { 0, 0, 0, fmt_9999, 0 };
    static cilist io___26 = { 0, 0, 0, fmt_9998, 0 };
    static cilist io___45 = { 0, 0, 0, fmt_9997, 0 };
    static cilist io___59 = { 0, 0, 0, fmt_9996, 0 };
    static cilist io___61 = { 0, 0, 0, fmt_9995, 0 };



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

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

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

/*  SCHKGB tests SGBTRF, -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. */

/*  NM      (input) INTEGER */
/*          The number of values of M contained in the vector MVAL. */

/*  MVAL    (input) INTEGER array, dimension (NM) */
/*          The values of the matrix row dimension M. */

/*  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 column dimension N. */

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

/*  NBVAL   (input) INTEGER array, dimension (NNB) */
/*          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. */

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

/*  LA      (input) INTEGER */
/*          The length of the array A.  LA >= (KLMAX+KUMAX+1)*NMAX */
/*          where KLMAX is the largest entry in the local array KLVAL, */
/*                KUMAX is the largest entry in the local array KUVAL and */
/*                NMAX is the largest entry in the input array NVAL. */

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

/*  LAFAC   (input) INTEGER */
/*          The length of the array AFAC. LAFAC >= (2*KLMAX+KUMAX+1)*NMAX */
/*          where KLMAX is the largest entry in the local array KLVAL, */
/*                KUMAX is the largest entry in the local array KUVAL and */
/*                NMAX is the largest entry in the input array NVAL. */

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

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

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

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

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

/*  IWORK   (workspace) INTEGER array, dimension (2*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;
    --afac;
    --a;
    --nsval;
    --nbval;
    --nval;
    --mval;
    --dotype;

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

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

    s_copy(path, "Single precision", (ftnlen)1, (ftnlen)16);
    s_copy(path + 1, "GB", (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) {
	serrge_(path, nout);
    }
    infoc_1.infot = 0;
    xlaenv_(&c__2, &c__2);

/*     Initialize the first value for the lower and upper bandwidths. */

    klval[0] = 0;
    kuval[0] = 0;

/*     Do for each value of M in MVAL */

    i__1 = *nm;
    for (im = 1; im <= i__1; ++im) {
	m = mval[im];

/*        Set values to use for the lower bandwidth. */

	klval[1] = m + (m + 1) / 4;

/*        KLVAL( 2 ) = MAX( M-1, 0 ) */

	klval[2] = (m * 3 - 1) / 4;
	klval[3] = (m + 1) / 4;

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

	i__2 = *nn;
	for (in = 1; in <= i__2; ++in) {
	    n = nval[in];
	    *(unsigned char *)xtype = 'N';

/*           Set values to use for the upper bandwidth. */

	    kuval[1] = n + (n + 1) / 4;

/*           KUVAL( 2 ) = MAX( N-1, 0 ) */

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

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

/* Computing MIN */
	    i__3 = m + 1;
	    nkl = min(i__3,4);
	    if (n == 0) {
		nkl = 2;
	    }
/* Computing MIN */
	    i__3 = n + 1;
	    nku = min(i__3,4);
	    if (m == 0) {
		nku = 2;
	    }
	    nimat = 8;
	    if (m <= 0 || n <= 0) {
		nimat = 1;
	    }

	    i__3 = nkl;
	    for (ikl = 1; ikl <= i__3; ++ikl) {

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

		kl = klval[ikl - 1];
		i__4 = nku;
		for (iku = 1; iku <= i__4; ++iku) {

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

		    ku = kuval[iku - 1];

/*                 Check that A and AFAC are big enough to generate this */
/*                 matrix. */

		    lda = kl + ku + 1;
		    ldafac = (kl << 1) + ku + 1;
		    if (lda * n > *la || ldafac * n > *lafac) {
			if (nfail == 0 && nerrs == 0) {
			    alahd_(nout, path);
			}
			if (n * (kl + ku + 1) > *la) {
			    io___25.ciunit = *nout;
			    s_wsfe(&io___25);
			    do_fio(&c__1, (char *)&(*la), (ftnlen)sizeof(
				    integer));
			    do_fio(&c__1, (char *)&m, (ftnlen)sizeof(integer))
				    ;
			    do_fio(&c__1, (char *)&n, (ftnlen)sizeof(integer))
				    ;
			    do_fio(&c__1, (char *)&kl, (ftnlen)sizeof(integer)
				    );
			    do_fio(&c__1, (char *)&ku, (ftnlen)sizeof(integer)
				    );
			    i__5 = n * (kl + ku + 1);
			    do_fio(&c__1, (char *)&i__5, (ftnlen)sizeof(
				    integer));
			    e_wsfe();
			    ++nerrs;
			}
			if (n * ((kl << 1) + ku + 1) > *lafac) {
			    io___26.ciunit = *nout;
			    s_wsfe(&io___26);
			    do_fio(&c__1, (char *)&(*lafac), (ftnlen)sizeof(
				    integer));
			    do_fio(&c__1, (char *)&m, (ftnlen)sizeof(integer))
				    ;
			    do_fio(&c__1, (char *)&n, (ftnlen)sizeof(integer))
				    ;
			    do_fio(&c__1, (char *)&kl, (ftnlen)sizeof(integer)
				    );
			    do_fio(&c__1, (char *)&ku, (ftnlen)sizeof(integer)
				    );
			    i__5 = n * ((kl << 1) + ku + 1);
			    do_fio(&c__1, (char *)&i__5, (ftnlen)sizeof(
				    integer));
			    e_wsfe();
			    ++nerrs;
			}
			goto L130;
		    }

		    i__5 = nimat;
		    for (imat = 1; imat <= i__5; ++imat) {

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

			if (! dotype[imat]) {
			    goto L120;
			}

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

			zerot = imat >= 2 && imat <= 4;
			if (zerot && n < imat - 1) {
			    goto L120;
			}

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

/*                       Set up parameters with SLATB4 and generate a */
/*                       test matrix with SLATMS. */

			    slatb4_(path, &imat, &m, &n, type__, &kl, &ku, &
				    anorm, &mode, &cndnum, dist);

/* Computing MAX */
			    i__6 = 1, i__7 = ku + 2 - n;
			    koff = max(i__6,i__7);
			    i__6 = koff - 1;
			    for (i__ = 1; i__ <= i__6; ++i__) {
				a[i__] = 0.f;
/* L20: */
			    }
			    s_copy(srnamc_1.srnamt, "SLATMS", (ftnlen)6, (
				    ftnlen)6);
			    slatms_(&m, &n, dist, iseed, type__, &rwork[1], &
				    mode, &cndnum, &anorm, &kl, &ku, "Z", &a[
				    koff], &lda, &work[1], &info);

/*                       Check the error code from SLATMS. */

			    if (info != 0) {
				alaerh_(path, "SLATMS", &info, &c__0, " ", &m, 
					 &n, &kl, &ku, &c_n1, &imat, &nfail, &
					nerrs, nout);
				goto L120;
			    }
			} else if (izero > 0) {

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

			    i__6 = i2 - i1 + 1;
			    scopy_(&i__6, &b[1], &c__1, &a[ioff + i1], &c__1);
			}

/*                    For types 2, 3, and 4, zero one or more columns of */
/*                    the matrix to test that INFO is returned correctly. */

			izero = 0;
			if (zerot) {
			    if (imat == 2) {
				izero = 1;
			    } else if (imat == 3) {
				izero = min(m,n);
			    } else {
				izero = min(m,n) / 2 + 1;
			    }
			    ioff = (izero - 1) * lda;
			    if (imat < 4) {

/*                          Store the column to be zeroed out in B. */

/* Computing MAX */
				i__6 = 1, i__7 = ku + 2 - izero;
				i1 = max(i__6,i__7);
/* Computing MIN */
				i__6 = kl + ku + 1, i__7 = ku + 1 + (m - 
					izero);
				i2 = min(i__6,i__7);
				i__6 = i2 - i1 + 1;
				scopy_(&i__6, &a[ioff + i1], &c__1, &b[1], &
					c__1);

				i__6 = i2;
				for (i__ = i1; i__ <= i__6; ++i__) {
				    a[ioff + i__] = 0.f;
/* L30: */
				}
			    } else {
				i__6 = n;
				for (j = izero; j <= i__6; ++j) {
/* Computing MAX */
				    i__7 = 1, i__8 = ku + 2 - j;
/* Computing MIN */
				    i__10 = kl + ku + 1, i__11 = ku + 1 + (m 
					    - j);
				    i__9 = min(i__10,i__11);
				    for (i__ = max(i__7,i__8); i__ <= i__9; 
					    ++i__) {
					a[ioff + i__] = 0.f;
/* L40: */
				    }
				    ioff += lda;
/* L50: */
				}
			    }
			}

/*                    These lines, if used in place of the calls in the */
/*                    loop over INB, cause the code to bomb on a Sun */
/*                    SPARCstation. */

/*                     ANORMO = SLANGB( 'O', N, KL, KU, A, LDA, RWORK ) */
/*                     ANORMI = SLANGB( 'I', N, KL, KU, A, LDA, RWORK ) */

/*                    Do for each blocksize in NBVAL */

			i__6 = *nnb;
			for (inb = 1; inb <= i__6; ++inb) {
			    nb = nbval[inb];
			    xlaenv_(&c__1, &nb);

/*                       Compute the LU factorization of the band matrix. */

			    if (m > 0 && n > 0) {
				i__9 = kl + ku + 1;
				slacpy_("Full", &i__9, &n, &a[1], &lda, &afac[
					kl + 1], &ldafac);
			    }
			    s_copy(srnamc_1.srnamt, "SGBTRF", (ftnlen)6, (
				    ftnlen)6);
			    sgbtrf_(&m, &n, &kl, &ku, &afac[1], &ldafac, &
				    iwork[1], &info);

/*                       Check error code from SGBTRF. */

			    if (info != izero) {
				alaerh_(path, "SGBTRF", &info, &izero, " ", &
					m, &n, &kl, &ku, &nb, &imat, &nfail, &
					nerrs, nout);
			    }
			    trfcon = FALSE_;

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

			    sgbt01_(&m, &n, &kl, &ku, &a[1], &lda, &afac[1], &
				    ldafac, &iwork[1], &work[1], result);

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

			    if (result[0] >= *thresh) {
				if (nfail == 0 && nerrs == 0) {
				    alahd_(nout, path);
				}
				io___45.ciunit = *nout;
				s_wsfe(&io___45);
				do_fio(&c__1, (char *)&m, (ftnlen)sizeof(
					integer));
				do_fio(&c__1, (char *)&n, (ftnlen)sizeof(
					integer));
				do_fio(&c__1, (char *)&kl, (ftnlen)sizeof(
					integer));
				do_fio(&c__1, (char *)&ku, (ftnlen)sizeof(
					integer));
				do_fio(&c__1, (char *)&nb, (ftnlen)sizeof(
					integer));
				do_fio(&c__1, (char *)&imat, (ftnlen)sizeof(
					integer));
				do_fio(&c__1, (char *)&c__1, (ftnlen)sizeof(
					integer));
				do_fio(&c__1, (char *)&result[0], (ftnlen)
					sizeof(real));
				e_wsfe();
				++nfail;
			    }
			    ++nrun;

/*                       Skip the remaining tests if this is not the */
/*                       first block size or if M .ne. N. */

			    if (inb > 1 || m != n) {
				goto L110;
			    }

			    anormo = slangb_("O", &n, &kl, &ku, &a[1], &lda, &
				    rwork[1]);
			    anormi = slangb_("I", &n, &kl, &ku, &a[1], &lda, &
				    rwork[1]);

			    if (info == 0) {

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

				ldb = max(1,n);
				slaset_("Full", &n, &n, &c_b63, &c_b64, &work[
					1], &ldb);
				s_copy(srnamc_1.srnamt, "SGBTRS", (ftnlen)6, (
					ftnlen)6);
				sgbtrs_("No transpose", &n, &kl, &ku, &n, &
					afac[1], &ldafac, &iwork[1], &work[1], 
					 &ldb, &info);

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

				ainvnm = slange_("O", &n, &n, &work[1], &ldb, 
					&rwork[1]);
				if (anormo <= 0.f || ainvnm <= 0.f) {
				    rcondo = 1.f;
				} else {
				    rcondo = 1.f / anormo / ainvnm;
				}

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

				ainvnm = slange_("I", &n, &n, &work[1], &ldb, 
					&rwork[1]);
				if (anormi <= 0.f || ainvnm <= 0.f) {
				    rcondi = 1.f;
				} else {
				    rcondi = 1.f / anormi / ainvnm;
				}
			    } else {

/*                          Do only the condition estimate if INFO.NE.0. */

				trfcon = TRUE_;
				rcondo = 0.f;
				rcondi = 0.f;
			    }

/*                       Skip the solve tests if the matrix is singular. */

			    if (trfcon) {
				goto L90;
			    }

			    i__9 = *nns;
			    for (irhs = 1; irhs <= i__9; ++irhs) {
				nrhs = nsval[irhs];
				*(unsigned char *)xtype = 'N';

				for (itran = 1; itran <= 3; ++itran) {
				    *(unsigned char *)trans = *(unsigned char 
					    *)&transs[itran - 1];
				    if (itran == 1) {
					rcondc = rcondo;
					*(unsigned char *)norm = 'O';
				    } else {
					rcondc = rcondi;
					*(unsigned char *)norm = 'I';
				    }

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

				    s_copy(srnamc_1.srnamt, "SLARHS", (ftnlen)
					    6, (ftnlen)6);
				    slarhs_(path, xtype, " ", trans, &n, &n, &
					    kl, &ku, &nrhs, &a[1], &lda, &
					    xact[1], &ldb, &b[1], &ldb, iseed, 
					     &info);
				    *(unsigned char *)xtype = 'C';
				    slacpy_("Full", &n, &nrhs, &b[1], &ldb, &
					    x[1], &ldb);

				    s_copy(srnamc_1.srnamt, "SGBTRS", (ftnlen)
					    6, (ftnlen)6);
				    sgbtrs_(trans, &n, &kl, &ku, &nrhs, &afac[
					    1], &ldafac, &iwork[1], &x[1], &
					    ldb, &info);

/*                             Check error code from SGBTRS. */

				    if (info != 0) {
					alaerh_(path, "SGBTRS", &info, &c__0, 
						trans, &n, &n, &kl, &ku, &
						c_n1, &imat, &nfail, &nerrs, 
						nout);
				    }

				    slacpy_("Full", &n, &nrhs, &b[1], &ldb, &
					    work[1], &ldb);
				    sgbt02_(trans, &m, &n, &kl, &ku, &nrhs, &
					    a[1], &lda, &x[1], &ldb, &work[1], 
					     &ldb, &result[1]);

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

				    sget04_(&n, &nrhs, &x[1], &ldb, &xact[1], 
					    &ldb, &rcondc, &result[2]);

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

				    s_copy(srnamc_1.srnamt, "SGBRFS", (ftnlen)
					    6, (ftnlen)6);
				    sgbrfs_(trans, &n, &kl, &ku, &nrhs, &a[1], 
					     &lda, &afac[1], &ldafac, &iwork[
					    1], &b[1], &ldb, &x[1], &ldb, &
					    rwork[1], &rwork[nrhs + 1], &work[
					    1], &iwork[n + 1], &info);

/*                             Check error code from SGBRFS. */

				    if (info != 0) {
					alaerh_(path, "SGBRFS", &info, &c__0, 
						trans, &n, &n, &kl, &ku, &
						nrhs, &imat, &nfail, &nerrs, 
						nout);
				    }

				    sget04_(&n, &nrhs, &x[1], &ldb, &xact[1], 
					    &ldb, &rcondc, &result[3]);
				    sgbt05_(trans, &n, &kl, &ku, &nrhs, &a[1], 
					     &lda, &b[1], &ldb, &x[1], &ldb, &
					    xact[1], &ldb, &rwork[1], &rwork[
					    nrhs + 1], &result[4]);
				    for (k = 2; k <= 6; ++k) {
					if (result[k - 1] >= *thresh) {
					    if (nfail == 0 && nerrs == 0) {
			  alahd_(nout, path);
					    }
					    io___59.ciunit = *nout;
					    s_wsfe(&io___59);
					    do_fio(&c__1, trans, (ftnlen)1);
					    do_fio(&c__1, (char *)&n, (ftnlen)
						    sizeof(integer));
					    do_fio(&c__1, (char *)&kl, (
						    ftnlen)sizeof(integer));
					    do_fio(&c__1, (char *)&ku, (
						    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;
					}
/* L60: */
				    }
				    nrun += 5;
/* L70: */
				}
/* L80: */
			    }

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

L90:
			    for (itran = 1; itran <= 2; ++itran) {
				if (itran == 1) {
				    anorm = anormo;
				    rcondc = rcondo;
				    *(unsigned char *)norm = 'O';
				} else {
				    anorm = anormi;
				    rcondc = rcondi;
				    *(unsigned char *)norm = 'I';
				}
				s_copy(srnamc_1.srnamt, "SGBCON", (ftnlen)6, (
					ftnlen)6);
				sgbcon_(norm, &n, &kl, &ku, &afac[1], &ldafac, 
					 &iwork[1], &anorm, &rcond, &work[1], 
					&iwork[n + 1], &info);

/*                             Check error code from SGBCON. */

				if (info != 0) {
				    alaerh_(path, "SGBCON", &info, &c__0, 
					    norm, &n, &n, &kl, &ku, &c_n1, &
					    imat, &nfail, &nerrs, nout);
				}

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

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

				if (result[6] >= *thresh) {
				    if (nfail == 0 && nerrs == 0) {
					alahd_(nout, path);
				    }
				    io___61.ciunit = *nout;
				    s_wsfe(&io___61);
				    do_fio(&c__1, norm, (ftnlen)1);
				    do_fio(&c__1, (char *)&n, (ftnlen)sizeof(
					    integer));
				    do_fio(&c__1, (char *)&kl, (ftnlen)sizeof(
					    integer));
				    do_fio(&c__1, (char *)&ku, (ftnlen)sizeof(
					    integer));
				    do_fio(&c__1, (char *)&imat, (ftnlen)
					    sizeof(integer));
				    do_fio(&c__1, (char *)&c__7, (ftnlen)
					    sizeof(integer));
				    do_fio(&c__1, (char *)&result[6], (ftnlen)
					    sizeof(real));
				    e_wsfe();
				    ++nfail;
				}
				++nrun;
/* L100: */
			    }

L110:
			    ;
			}
L120:
			;
		    }
L130:
		    ;
		}
/* L140: */
	    }
/* L150: */
	}
/* L160: */
    }

/*     Print a summary of the results. */

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


    return 0;

/*     End of SCHKGB */

} /* schkgb_ */
Example #4
0
/* Subroutine */ int sgbrfsx_(char *trans, char *equed, integer *n, integer *
	kl, integer *ku, integer *nrhs, real *ab, integer *ldab, real *afb, 
	integer *ldafb, integer *ipiv, real *r__, real *c__, real *b, integer 
	*ldb, real *x, integer *ldx, real *rcond, real *berr, integer *
	n_err_bnds__, real *err_bnds_norm__, real *err_bnds_comp__, integer *
	nparams, real *params, real *work, integer *iwork, integer *info)
{
    /* System generated locals */
    integer ab_dim1, ab_offset, afb_dim1, afb_offset, b_dim1, b_offset, 
	    x_dim1, x_offset, err_bnds_norm_dim1, err_bnds_norm_offset, 
	    err_bnds_comp_dim1, err_bnds_comp_offset, i__1;
    real r__1, r__2;

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

    /* Local variables */
    real illrcond_thresh__, unstable_thresh__, err_lbnd__;
    integer ref_type__;
    extern integer ilatrans_(char *);
    integer j;
    real rcond_tmp__;
    integer prec_type__, trans_type__;
    extern doublereal sla_gbrcond__(char *, integer *, integer *, integer *, 
	    real *, integer *, real *, integer *, integer *, integer *, real *
	    , integer *, real *, integer *, ftnlen);
    real cwise_wrong__;
    extern /* Subroutine */ int sla_gbrfsx_extended__(integer *, integer *, 
	    integer *, integer *, integer *, integer *, real *, integer *, 
	    real *, integer *, integer *, logical *, real *, real *, integer *
	    , real *, integer *, real *, integer *, real *, real *, real *, 
	    real *, real *, real *, real *, integer *, real *, real *, 
	    logical *, integer *);
    char norm[1];
    logical ignore_cwise__;
    extern logical lsame_(char *, char *);
    real anorm;
    extern doublereal slangb_(char *, integer *, integer *, integer *, real *, 
	     integer *, real *), slamch_(char *);
    extern /* Subroutine */ int sgbcon_(char *, integer *, integer *, integer 
	    *, real *, integer *, integer *, real *, real *, real *, integer *
, integer *), xerbla_(char *, integer *);
    logical colequ, notran, rowequ;
    extern integer ilaprec_(char *);
    integer ithresh, n_norms__;
    real rthresh;


/*     -- 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 */
/*     ======= */

/*     SGBRFSX improves the computed solution to a system of linear */
/*     equations and provides error bounds and backward error estimates */
/*     for the solution.  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. */

/*     The original system of linear equations may have been equilibrated */
/*     before calling this routine, as described by arguments EQUED, R */
/*     and C below. In this case, the solution and error bounds returned */
/*     are for the original unequilibrated system. */

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

/*     Some optional parameters are bundled in the PARAMS array.  These */
/*     settings determine how refinement is performed, but often the */
/*     defaults are acceptable.  If the defaults are acceptable, users */
/*     can pass NPARAMS = 0 which prevents the source code from accessing */
/*     the PARAMS argument. */

/*     TRANS   (input) CHARACTER*1 */
/*     Specifies the form of the system of equations: */
/*       = 'N':  A * X = B     (No transpose) */
/*       = 'T':  A**T * X = B  (Transpose) */
/*       = 'C':  A**H * X = B  (Conjugate transpose = Transpose) */

/*     EQUED   (input) CHARACTER*1 */
/*     Specifies the form of equilibration that was done to A */
/*     before calling this routine. This is needed to compute */
/*     the solution and error bounds correctly. */
/*       = 'N':  No equilibration */
/*       = 'R':  Row equilibration, i.e., A has been premultiplied by */
/*               diag(R). */
/*       = 'C':  Column equilibration, i.e., A has been postmultiplied */
/*               by diag(C). */
/*       = 'B':  Both row and column equilibration, i.e., A has been */
/*               replaced by diag(R) * A * diag(C). */
/*               The right hand side B has been changed accordingly. */

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

/*     KL      (input) INTEGER */
/*     The number of subdiagonals within the band of A.  KL >= 0. */

/*     KU      (input) INTEGER */
/*     The number of superdiagonals within the band of A.  KU >= 0. */

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

/*     AB      (input) DOUBLE PRECISION array, dimension (LDAB,N) */
/*     The original band matrix A, stored in rows 1 to KL+KU+1. */
/*     The j-th column of A is stored in the j-th column of the */
/*     array AB as follows: */
/*     AB(ku+1+i-j,j) = A(i,j) for max(1,j-ku)<=i<=min(n,j+kl). */

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

/*     AFB     (input) DOUBLE PRECISION array, dimension (LDAFB,N) */
/*     Details of the LU factorization of the band matrix A, as */
/*     computed by DGBTRF.  U is stored as an upper triangular band */
/*     matrix with KL+KU superdiagonals in rows 1 to KL+KU+1, and */
/*     the multipliers used during the factorization are stored in */
/*     rows KL+KU+2 to 2*KL+KU+1. */

/*     LDAFB   (input) INTEGER */
/*     The leading dimension of the array AFB.  LDAFB >= 2*KL*KU+1. */

/*     IPIV    (input) INTEGER array, dimension (N) */
/*     The pivot indices from SGETRF; for 1<=i<=N, row i of the */
/*     matrix was interchanged with row IPIV(i). */

/*     R       (input or output) REAL array, dimension (N) */
/*     The row scale factors for A.  If EQUED = 'R' or 'B', A is */
/*     multiplied on the left by diag(R); if EQUED = 'N' or 'C', R */
/*     is not accessed.  R is an input argument if FACT = 'F'; */
/*     otherwise, R is an output argument.  If FACT = 'F' and */
/*     EQUED = 'R' or 'B', each element of R must be positive. */
/*     If R is output, each element of R is a power of the radix. */
/*     If R is input, each element of R 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. */

/*     C       (input or output) REAL array, dimension (N) */
/*     The column scale factors for A.  If EQUED = 'C' or 'B', A is */
/*     multiplied on the right by diag(C); if EQUED = 'N' or 'R', C */
/*     is not accessed.  C is an input argument if FACT = 'F'; */
/*     otherwise, C is an output argument.  If FACT = 'F' and */
/*     EQUED = 'C' or 'B', each element of C must be positive. */
/*     If C is output, each element of C is a power of the radix. */
/*     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) REAL 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) REAL array, dimension (LDX,NRHS) */
/*     On entry, the solution matrix X, as computed by SGETRS. */
/*     On exit, the improved solution matrix X. */

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

/*     RCOND   (output) 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. */

/*     BERR    (output) REAL array, dimension (NRHS) */
/*     Componentwise relative backward error.  This is 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). */

/*     N_ERR_BNDS (input) INTEGER */
/*     Number of error bounds to return for each right hand side */
/*     and each type (normwise or componentwise).  See ERR_BNDS_NORM and */
/*     ERR_BNDS_COMP below. */

/*     ERR_BNDS_NORM  (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. */

/*     See Lapack Working Note 165 for further details and extra */
/*     cautions. */

/*     ERR_BNDS_COMP  (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. */

/*     See Lapack Working Note 165 for further details and extra */
/*     cautions. */

/*     NPARAMS (input) INTEGER */
/*     Specifies the number of parameters set in PARAMS.  If .LE. 0, the */
/*     PARAMS array is never referenced and default values are used. */

/*     PARAMS  (input / output) REAL array, dimension NPARAMS */
/*     Specifies algorithm parameters.  If an entry is .LT. 0.0, then */
/*     that entry will be filled with default value used for that */
/*     parameter.  Only positions up to NPARAMS are accessed; defaults */
/*     are used for higher-numbered parameters. */

/*       PARAMS(LA_LINRX_ITREF_I = 1) : Whether to perform iterative */
/*            refinement or not. */
/*         Default: 1.0 */
/*            = 0.0 : No refinement is performed, and no error bounds are */
/*                    computed. */
/*            = 1.0 : Use the double-precision refinement algorithm, */
/*                    possibly with doubled-single computations if the */
/*                    compilation environment does not support DOUBLE */
/*                    PRECISION. */
/*              (other values are reserved for future use) */

/*       PARAMS(LA_LINRX_ITHRESH_I = 2) : Maximum number of residual */
/*            computations allowed for refinement. */
/*         Default: 10 */
/*         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. */

/*       PARAMS(LA_LINRX_CWISE_I = 3) : Flag determining if the code */
/*            will attempt to find a solution with small componentwise */
/*            relative error in the double-precision algorithm.  Positive */
/*            is true, 0.0 is false. */
/*         Default: 1.0 (attempt componentwise convergence) */

/*     WORK    (workspace) REAL array, dimension (4*N) */

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

/*     INFO    (output) INTEGER */
/*       = 0:  Successful exit. The solution to every right-hand side is */
/*         guaranteed. */
/*       < 0:  If INFO = -i, the i-th argument had an illegal value */
/*       > 0 and <= N:  U(INFO,INFO) is exactly zero.  The factorization */
/*         has been completed, but the factor U is exactly singular, so */
/*         the solution and error bounds could not be computed. RCOND = 0 */
/*         is returned. */
/*       = N+J: The solution corresponding to the Jth right-hand side is */
/*         not guaranteed. The solutions corresponding to other right- */
/*         hand sides K with K > J may not be guaranteed as well, but */
/*         only the first such right-hand side is reported. If a small */
/*         componentwise error is not requested (PARAMS(3) = 0.0) then */
/*         the Jth right-hand side is the first with a normwise error */
/*         bound that is not guaranteed (the smallest J such */
/*         that ERR_BNDS_NORM(J,1) = 0.0). By default (PARAMS(3) = 1.0) */
/*         the Jth right-hand side is the first with either a normwise or */
/*         componentwise error bound that is not guaranteed (the smallest */
/*         J such that either ERR_BNDS_NORM(J,1) = 0.0 or */
/*         ERR_BNDS_COMP(J,1) = 0.0). See the definition of */
/*         ERR_BNDS_NORM(:,1) and ERR_BNDS_COMP(:,1). To get information */
/*         about all of the right-hand sides check ERR_BNDS_NORM or */
/*         ERR_BNDS_COMP. */

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

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

/*     Check the input parameters. */

    /* 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;
    ab_dim1 = *ldab;
    ab_offset = 1 + ab_dim1;
    ab -= ab_offset;
    afb_dim1 = *ldafb;
    afb_offset = 1 + afb_dim1;
    afb -= afb_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;
    --berr;
    --params;
    --work;
    --iwork;

    /* Function Body */
    *info = 0;
    trans_type__ = ilatrans_(trans);
    ref_type__ = 1;
    if (*nparams >= 1) {
	if (params[1] < 0.f) {
	    params[1] = 1.f;
	} else {
	    ref_type__ = params[1];
	}
    }

/*     Set default parameters. */

    illrcond_thresh__ = (real) (*n) * slamch_("Epsilon");
    ithresh = 10;
    rthresh = .5f;
    unstable_thresh__ = .25f;
    ignore_cwise__ = FALSE_;

    if (*nparams >= 2) {
	if (params[2] < 0.f) {
	    params[2] = (real) ithresh;
	} else {
	    ithresh = (integer) params[2];
	}
    }
    if (*nparams >= 3) {
	if (params[3] < 0.f) {
	    if (ignore_cwise__) {
		params[3] = 0.f;
	    } else {
		params[3] = 1.f;
	    }
	} else {
	    ignore_cwise__ = params[3] == 0.f;
	}
    }
    if (ref_type__ == 0 || *n_err_bnds__ == 0) {
	n_norms__ = 0;
    } else if (ignore_cwise__) {
	n_norms__ = 1;
    } else {
	n_norms__ = 2;
    }

    notran = lsame_(trans, "N");
    rowequ = lsame_(equed, "R") || lsame_(equed, "B");
    colequ = lsame_(equed, "C") || lsame_(equed, "B");

/*     Test input parameters. */

    if (trans_type__ == -1) {
	*info = -1;
    } else if (! rowequ && ! colequ && ! lsame_(equed, "N")) {
	*info = -2;
    } else if (*n < 0) {
	*info = -3;
    } else if (*kl < 0) {
	*info = -4;
    } else if (*ku < 0) {
	*info = -5;
    } else if (*nrhs < 0) {
	*info = -6;
    } else if (*ldab < *kl + *ku + 1) {
	*info = -8;
    } else if (*ldafb < (*kl << 1) + *ku + 1) {
	*info = -10;
    } else if (*ldb < max(1,*n)) {
	*info = -13;
    } else if (*ldx < max(1,*n)) {
	*info = -15;
    }
    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("SGBRFSX", &i__1);
	return 0;
    }

/*     Quick return if possible. */

    if (*n == 0 || *nrhs == 0) {
	*rcond = 1.f;
	i__1 = *nrhs;
	for (j = 1; j <= i__1; ++j) {
	    berr[j] = 0.f;
	    if (*n_err_bnds__ >= 1) {
		err_bnds_norm__[j + err_bnds_norm_dim1] = 1.f;
		err_bnds_comp__[j + err_bnds_comp_dim1] = 1.f;
	    } else if (*n_err_bnds__ >= 2) {
		err_bnds_norm__[j + (err_bnds_norm_dim1 << 1)] = 0.f;
		err_bnds_comp__[j + (err_bnds_comp_dim1 << 1)] = 0.f;
	    } else if (*n_err_bnds__ >= 3) {
		err_bnds_norm__[j + err_bnds_norm_dim1 * 3] = 1.f;
		err_bnds_comp__[j + err_bnds_comp_dim1 * 3] = 1.f;
	    }
	}
	return 0;
    }

/*     Default to failure. */

    *rcond = 0.f;
    i__1 = *nrhs;
    for (j = 1; j <= i__1; ++j) {
	berr[j] = 1.f;
	if (*n_err_bnds__ >= 1) {
	    err_bnds_norm__[j + err_bnds_norm_dim1] = 1.f;
	    err_bnds_comp__[j + err_bnds_comp_dim1] = 1.f;
	} else if (*n_err_bnds__ >= 2) {
	    err_bnds_norm__[j + (err_bnds_norm_dim1 << 1)] = 1.f;
	    err_bnds_comp__[j + (err_bnds_comp_dim1 << 1)] = 1.f;
	} else if (*n_err_bnds__ >= 3) {
	    err_bnds_norm__[j + err_bnds_norm_dim1 * 3] = 0.f;
	    err_bnds_comp__[j + err_bnds_comp_dim1 * 3] = 0.f;
	}
    }

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

    if (notran) {
	*(unsigned char *)norm = 'I';
    } else {
	*(unsigned char *)norm = '1';
    }
    anorm = slangb_(norm, n, kl, ku, &ab[ab_offset], ldab, &work[1]);
    sgbcon_(norm, n, kl, ku, &afb[afb_offset], ldafb, &ipiv[1], &anorm, rcond, 
	     &work[1], &iwork[1], info);

/*     Perform refinement on each right-hand side */

    if (ref_type__ != 0) {
	prec_type__ = ilaprec_("D");
	if (notran) {
	    sla_gbrfsx_extended__(&prec_type__, &trans_type__, n, kl, ku, 
		    nrhs, &ab[ab_offset], ldab, &afb[afb_offset], ldafb, &
		    ipiv[1], &colequ, &c__[1], &b[b_offset], ldb, &x[x_offset]
		    , ldx, &berr[1], &n_norms__, &err_bnds_norm__[
		    err_bnds_norm_offset], &err_bnds_comp__[
		    err_bnds_comp_offset], &work[*n + 1], &work[1], &work[(*n 
		    << 1) + 1], &work[1], rcond, &ithresh, &rthresh, &
		    unstable_thresh__, &ignore_cwise__, info);
	} else {
	    sla_gbrfsx_extended__(&prec_type__, &trans_type__, n, kl, ku, 
		    nrhs, &ab[ab_offset], ldab, &afb[afb_offset], ldafb, &
		    ipiv[1], &rowequ, &r__[1], &b[b_offset], ldb, &x[x_offset]
		    , ldx, &berr[1], &n_norms__, &err_bnds_norm__[
		    err_bnds_norm_offset], &err_bnds_comp__[
		    err_bnds_comp_offset], &work[*n + 1], &work[1], &work[(*n 
		    << 1) + 1], &work[1], rcond, &ithresh, &rthresh, &
		    unstable_thresh__, &ignore_cwise__, info);
	}
    }
/* Computing MAX */
    r__1 = 10.f, r__2 = sqrt((real) (*n));
    err_lbnd__ = dmax(r__1,r__2) * slamch_("Epsilon");
    if (*n_err_bnds__ >= 1 && n_norms__ >= 1) {

/*     Compute scaled normwise condition number cond(A*C). */

	if (colequ && notran) {
	    rcond_tmp__ = sla_gbrcond__(trans, n, kl, ku, &ab[ab_offset], 
		    ldab, &afb[afb_offset], ldafb, &ipiv[1], &c_n1, &c__[1], 
		    info, &work[1], &iwork[1], (ftnlen)1);
	} else if (rowequ && ! notran) {
	    rcond_tmp__ = sla_gbrcond__(trans, n, kl, ku, &ab[ab_offset], 
		    ldab, &afb[afb_offset], ldafb, &ipiv[1], &c_n1, &r__[1], 
		    info, &work[1], &iwork[1], (ftnlen)1);
	} else {
	    rcond_tmp__ = sla_gbrcond__(trans, n, kl, ku, &ab[ab_offset], 
		    ldab, &afb[afb_offset], ldafb, &ipiv[1], &c__0, &r__[1], 
		    info, &work[1], &iwork[1], (ftnlen)1);
	}
	i__1 = *nrhs;
	for (j = 1; j <= i__1; ++j) {

/*     Cap the error at 1.0. */

	    if (*n_err_bnds__ >= 2 && err_bnds_norm__[j + (err_bnds_norm_dim1 
		    << 1)] > 1.f) {
		err_bnds_norm__[j + (err_bnds_norm_dim1 << 1)] = 1.f;
	    }

/*     Threshold the error (see LAWN). */

	    if (rcond_tmp__ < illrcond_thresh__) {
		err_bnds_norm__[j + (err_bnds_norm_dim1 << 1)] = 1.f;
		err_bnds_norm__[j + err_bnds_norm_dim1] = 0.f;
		if (*info <= *n) {
		    *info = *n + j;
		}
	    } else if (err_bnds_norm__[j + (err_bnds_norm_dim1 << 1)] < 
		    err_lbnd__) {
		err_bnds_norm__[j + (err_bnds_norm_dim1 << 1)] = err_lbnd__;
		err_bnds_norm__[j + err_bnds_norm_dim1] = 1.f;
	    }

/*     Save the condition number. */

	    if (*n_err_bnds__ >= 3) {
		err_bnds_norm__[j + err_bnds_norm_dim1 * 3] = rcond_tmp__;
	    }
	}
    }
    if (*n_err_bnds__ >= 1 && n_norms__ >= 2) {

/*     Compute componentwise condition number cond(A*diag(Y(:,J))) for */
/*     each right-hand side using the current solution as an estimate of */
/*     the true solution.  If the componentwise error estimate is too */
/*     large, then the solution is a lousy estimate of truth and the */
/*     estimated RCOND may be too optimistic.  To avoid misleading users, */
/*     the inverse condition number is set to 0.0 when the estimated */
/*     cwise error is at least CWISE_WRONG. */

	cwise_wrong__ = sqrt(slamch_("Epsilon"));
	i__1 = *nrhs;
	for (j = 1; j <= i__1; ++j) {
	    if (err_bnds_comp__[j + (err_bnds_comp_dim1 << 1)] < 
		    cwise_wrong__) {
		rcond_tmp__ = sla_gbrcond__(trans, n, kl, ku, &ab[ab_offset], 
			ldab, &afb[afb_offset], ldafb, &ipiv[1], &c__1, &x[j *
			 x_dim1 + 1], info, &work[1], &iwork[1], (ftnlen)1);
	    } else {
		rcond_tmp__ = 0.f;
	    }

/*     Cap the error at 1.0. */

	    if (*n_err_bnds__ >= 2 && err_bnds_comp__[j + (err_bnds_comp_dim1 
		    << 1)] > 1.f) {
		err_bnds_comp__[j + (err_bnds_comp_dim1 << 1)] = 1.f;
	    }

/*     Threshold the error (see LAWN). */

	    if (rcond_tmp__ < illrcond_thresh__) {
		err_bnds_comp__[j + (err_bnds_comp_dim1 << 1)] = 1.f;
		err_bnds_comp__[j + err_bnds_comp_dim1] = 0.f;
		if (params[3] == 1.f && *info < *n + j) {
		    *info = *n + j;
		}
	    } else if (err_bnds_comp__[j + (err_bnds_comp_dim1 << 1)] < 
		    err_lbnd__) {
		err_bnds_comp__[j + (err_bnds_comp_dim1 << 1)] = err_lbnd__;
		err_bnds_comp__[j + err_bnds_comp_dim1] = 1.f;
	    }

/*     Save the condition number. */

	    if (*n_err_bnds__ >= 3) {
		err_bnds_comp__[j + err_bnds_comp_dim1 * 3] = rcond_tmp__;
	    }
	}
    }

    return 0;

/*     End of SGBRFSX */

} /* sgbrfsx_ */