예제 #1
0
파일: derrge.c 프로젝트: kstraube/hysim
/* Subroutine */ int derrge_(char *path, integer *nunit)
{
    /* Builtin functions */
    integer s_wsle(cilist *), e_wsle(void);
    /* Subroutine */ int s_copy(char *, char *, ftnlen, ftnlen);

    /* Local variables */
    doublereal a[16]	/* was [4][4] */, b[4];
    integer i__, j;
    doublereal w[12], x[4];
    char c2[2];
    doublereal r1[4], r2[4], af[16]	/* was [4][4] */;
    integer ip[4], iw[4], info;
    doublereal anrm, ccond, rcond;
    extern /* Subroutine */ int dgbtf2_(integer *, integer *, integer *, 
	    integer *, doublereal *, integer *, integer *, integer *), 
	    dgetf2_(integer *, integer *, doublereal *, integer *, integer *, 
	    integer *), dgbcon_(char *, integer *, integer *, integer *, 
	    doublereal *, integer *, integer *, doublereal *, doublereal *, 
	    doublereal *, integer *, integer *), dgecon_(char *, 
	    integer *, doublereal *, integer *, doublereal *, doublereal *, 
	    doublereal *, integer *, integer *), alaesm_(char *, 
	    logical *, integer *), dgbequ_(integer *, integer *, 
	    integer *, integer *, doublereal *, integer *, doublereal *, 
	    doublereal *, doublereal *, doublereal *, doublereal *, integer *)
	    , dgbrfs_(char *, integer *, integer *, integer *, integer *, 
	    doublereal *, integer *, doublereal *, integer *, integer *, 
	    doublereal *, integer *, doublereal *, integer *, doublereal *, 
	    doublereal *, doublereal *, integer *, integer *), 
	    dgbtrf_(integer *, integer *, integer *, integer *, doublereal *, 
	    integer *, integer *, integer *), dgeequ_(integer *, integer *, 
	    doublereal *, integer *, doublereal *, doublereal *, doublereal *, 
	     doublereal *, doublereal *, integer *), dgerfs_(char *, integer *
, integer *, doublereal *, integer *, doublereal *, integer *, 
	    integer *, doublereal *, integer *, doublereal *, integer *, 
	    doublereal *, doublereal *, doublereal *, integer *, integer *), dgetrf_(integer *, integer *, doublereal *, integer *, 
	    integer *, integer *), dgetri_(integer *, doublereal *, integer *, 
	     integer *, doublereal *, integer *, integer *);
    extern logical lsamen_(integer *, char *, char *);
    extern /* Subroutine */ int chkxer_(char *, integer *, integer *, logical 
	    *, logical *), dgbtrs_(char *, integer *, integer *, 
	    integer *, integer *, doublereal *, integer *, integer *, 
	    doublereal *, integer *, integer *), dgetrs_(char *, 
	    integer *, integer *, doublereal *, integer *, integer *, 
	    doublereal *, integer *, integer *);

    /* Fortran I/O blocks */
    static cilist io___1 = { 0, 0, 0, 0, 0 };



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

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

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

/*  DERRGE tests the error exits for the DOUBLE PRECISION routines */
/*  for general matrices. */

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

/*  PATH    (input) CHARACTER*3 */
/*          The LAPACK path name for the routines to be tested. */

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

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

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

    infoc_1.nout = *nunit;
    io___1.ciunit = infoc_1.nout;
    s_wsle(&io___1);
    e_wsle();
    s_copy(c2, path + 1, (ftnlen)2, (ftnlen)2);

/*     Set the variables to innocuous values. */

    for (j = 1; j <= 4; ++j) {
	for (i__ = 1; i__ <= 4; ++i__) {
	    a[i__ + (j << 2) - 5] = 1. / (doublereal) (i__ + j);
	    af[i__ + (j << 2) - 5] = 1. / (doublereal) (i__ + j);
/* L10: */
	}
	b[j - 1] = 0.;
	r1[j - 1] = 0.;
	r2[j - 1] = 0.;
	w[j - 1] = 0.;
	x[j - 1] = 0.;
	ip[j - 1] = j;
	iw[j - 1] = j;
/* L20: */
    }
    infoc_1.ok = TRUE_;

    if (lsamen_(&c__2, c2, "GE")) {

/*        Test error exits of the routines that use the LU decomposition */
/*        of a general matrix. */

/*        DGETRF */

	s_copy(srnamc_1.srnamt, "DGETRF", (ftnlen)6, (ftnlen)6);
	infoc_1.infot = 1;
	dgetrf_(&c_n1, &c__0, a, &c__1, ip, &info);
	chkxer_("DGETRF", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 2;
	dgetrf_(&c__0, &c_n1, a, &c__1, ip, &info);
	chkxer_("DGETRF", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 4;
	dgetrf_(&c__2, &c__1, a, &c__1, ip, &info);
	chkxer_("DGETRF", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);

/*        DGETF2 */

	s_copy(srnamc_1.srnamt, "DGETF2", (ftnlen)6, (ftnlen)6);
	infoc_1.infot = 1;
	dgetf2_(&c_n1, &c__0, a, &c__1, ip, &info);
	chkxer_("DGETF2", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 2;
	dgetf2_(&c__0, &c_n1, a, &c__1, ip, &info);
	chkxer_("DGETF2", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 4;
	dgetf2_(&c__2, &c__1, a, &c__1, ip, &info);
	chkxer_("DGETF2", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);

/*        DGETRI */

	s_copy(srnamc_1.srnamt, "DGETRI", (ftnlen)6, (ftnlen)6);
	infoc_1.infot = 1;
	dgetri_(&c_n1, a, &c__1, ip, w, &c__12, &info);
	chkxer_("DGETRI", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 3;
	dgetri_(&c__2, a, &c__1, ip, w, &c__12, &info);
	chkxer_("DGETRI", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);

/*        DGETRS */

	s_copy(srnamc_1.srnamt, "DGETRS", (ftnlen)6, (ftnlen)6);
	infoc_1.infot = 1;
	dgetrs_("/", &c__0, &c__0, a, &c__1, ip, b, &c__1, &info);
	chkxer_("DGETRS", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 2;
	dgetrs_("N", &c_n1, &c__0, a, &c__1, ip, b, &c__1, &info);
	chkxer_("DGETRS", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 3;
	dgetrs_("N", &c__0, &c_n1, a, &c__1, ip, b, &c__1, &info);
	chkxer_("DGETRS", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 5;
	dgetrs_("N", &c__2, &c__1, a, &c__1, ip, b, &c__2, &info);
	chkxer_("DGETRS", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 8;
	dgetrs_("N", &c__2, &c__1, a, &c__2, ip, b, &c__1, &info);
	chkxer_("DGETRS", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);

/*        DGERFS */

	s_copy(srnamc_1.srnamt, "DGERFS", (ftnlen)6, (ftnlen)6);
	infoc_1.infot = 1;
	dgerfs_("/", &c__0, &c__0, a, &c__1, af, &c__1, ip, b, &c__1, x, &
		c__1, r1, r2, w, iw, &info);
	chkxer_("DGERFS", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 2;
	dgerfs_("N", &c_n1, &c__0, a, &c__1, af, &c__1, ip, b, &c__1, x, &
		c__1, r1, r2, w, iw, &info);
	chkxer_("DGERFS", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 3;
	dgerfs_("N", &c__0, &c_n1, a, &c__1, af, &c__1, ip, b, &c__1, x, &
		c__1, r1, r2, w, iw, &info);
	chkxer_("DGERFS", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 5;
	dgerfs_("N", &c__2, &c__1, a, &c__1, af, &c__2, ip, b, &c__2, x, &
		c__2, r1, r2, w, iw, &info);
	chkxer_("DGERFS", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 7;
	dgerfs_("N", &c__2, &c__1, a, &c__2, af, &c__1, ip, b, &c__2, x, &
		c__2, r1, r2, w, iw, &info);
	chkxer_("DGERFS", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 10;
	dgerfs_("N", &c__2, &c__1, a, &c__2, af, &c__2, ip, b, &c__1, x, &
		c__2, r1, r2, w, iw, &info);
	chkxer_("DGERFS", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 12;
	dgerfs_("N", &c__2, &c__1, a, &c__2, af, &c__2, ip, b, &c__2, x, &
		c__1, r1, r2, w, iw, &info);
	chkxer_("DGERFS", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);

/*        DGECON */

	s_copy(srnamc_1.srnamt, "DGECON", (ftnlen)6, (ftnlen)6);
	infoc_1.infot = 1;
	dgecon_("/", &c__0, a, &c__1, &anrm, &rcond, w, iw, &info);
	chkxer_("DGECON", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 2;
	dgecon_("1", &c_n1, a, &c__1, &anrm, &rcond, w, iw, &info);
	chkxer_("DGECON", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 4;
	dgecon_("1", &c__2, a, &c__1, &anrm, &rcond, w, iw, &info);
	chkxer_("DGECON", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);

/*        DGEEQU */

	s_copy(srnamc_1.srnamt, "DGEEQU", (ftnlen)6, (ftnlen)6);
	infoc_1.infot = 1;
	dgeequ_(&c_n1, &c__0, a, &c__1, r1, r2, &rcond, &ccond, &anrm, &info);
	chkxer_("DGEEQU", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 2;
	dgeequ_(&c__0, &c_n1, a, &c__1, r1, r2, &rcond, &ccond, &anrm, &info);
	chkxer_("DGEEQU", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 4;
	dgeequ_(&c__2, &c__2, a, &c__1, r1, r2, &rcond, &ccond, &anrm, &info);
	chkxer_("DGEEQU", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);

    } else if (lsamen_(&c__2, c2, "GB")) {

/*        Test error exits of the routines that use the LU decomposition */
/*        of a general band matrix. */

/*        DGBTRF */

	s_copy(srnamc_1.srnamt, "DGBTRF", (ftnlen)6, (ftnlen)6);
	infoc_1.infot = 1;
	dgbtrf_(&c_n1, &c__0, &c__0, &c__0, a, &c__1, ip, &info);
	chkxer_("DGBTRF", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 2;
	dgbtrf_(&c__0, &c_n1, &c__0, &c__0, a, &c__1, ip, &info);
	chkxer_("DGBTRF", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 3;
	dgbtrf_(&c__1, &c__1, &c_n1, &c__0, a, &c__1, ip, &info);
	chkxer_("DGBTRF", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 4;
	dgbtrf_(&c__1, &c__1, &c__0, &c_n1, a, &c__1, ip, &info);
	chkxer_("DGBTRF", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 6;
	dgbtrf_(&c__2, &c__2, &c__1, &c__1, a, &c__3, ip, &info);
	chkxer_("DGBTRF", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);

/*        DGBTF2 */

	s_copy(srnamc_1.srnamt, "DGBTF2", (ftnlen)6, (ftnlen)6);
	infoc_1.infot = 1;
	dgbtf2_(&c_n1, &c__0, &c__0, &c__0, a, &c__1, ip, &info);
	chkxer_("DGBTF2", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 2;
	dgbtf2_(&c__0, &c_n1, &c__0, &c__0, a, &c__1, ip, &info);
	chkxer_("DGBTF2", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 3;
	dgbtf2_(&c__1, &c__1, &c_n1, &c__0, a, &c__1, ip, &info);
	chkxer_("DGBTF2", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 4;
	dgbtf2_(&c__1, &c__1, &c__0, &c_n1, a, &c__1, ip, &info);
	chkxer_("DGBTF2", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 6;
	dgbtf2_(&c__2, &c__2, &c__1, &c__1, a, &c__3, ip, &info);
	chkxer_("DGBTF2", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);

/*        DGBTRS */

	s_copy(srnamc_1.srnamt, "DGBTRS", (ftnlen)6, (ftnlen)6);
	infoc_1.infot = 1;
	dgbtrs_("/", &c__0, &c__0, &c__0, &c__1, a, &c__1, ip, b, &c__1, &
		info);
	chkxer_("DGBTRS", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 2;
	dgbtrs_("N", &c_n1, &c__0, &c__0, &c__1, a, &c__1, ip, b, &c__1, &
		info);
	chkxer_("DGBTRS", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 3;
	dgbtrs_("N", &c__1, &c_n1, &c__0, &c__1, a, &c__1, ip, b, &c__1, &
		info);
	chkxer_("DGBTRS", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 4;
	dgbtrs_("N", &c__1, &c__0, &c_n1, &c__1, a, &c__1, ip, b, &c__1, &
		info);
	chkxer_("DGBTRS", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 5;
	dgbtrs_("N", &c__1, &c__0, &c__0, &c_n1, a, &c__1, ip, b, &c__1, &
		info);
	chkxer_("DGBTRS", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 7;
	dgbtrs_("N", &c__2, &c__1, &c__1, &c__1, a, &c__3, ip, b, &c__2, &
		info);
	chkxer_("DGBTRS", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 10;
	dgbtrs_("N", &c__2, &c__0, &c__0, &c__1, a, &c__1, ip, b, &c__1, &
		info);
	chkxer_("DGBTRS", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);

/*        DGBRFS */

	s_copy(srnamc_1.srnamt, "DGBRFS", (ftnlen)6, (ftnlen)6);
	infoc_1.infot = 1;
	dgbrfs_("/", &c__0, &c__0, &c__0, &c__0, a, &c__1, af, &c__1, ip, b, &
		c__1, x, &c__1, r1, r2, w, iw, &info);
	chkxer_("DGBRFS", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 2;
	dgbrfs_("N", &c_n1, &c__0, &c__0, &c__0, a, &c__1, af, &c__1, ip, b, &
		c__1, x, &c__1, r1, r2, w, iw, &info);
	chkxer_("DGBRFS", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 3;
	dgbrfs_("N", &c__1, &c_n1, &c__0, &c__0, a, &c__1, af, &c__1, ip, b, &
		c__1, x, &c__1, r1, r2, w, iw, &info);
	chkxer_("DGBRFS", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 4;
	dgbrfs_("N", &c__1, &c__0, &c_n1, &c__0, a, &c__1, af, &c__1, ip, b, &
		c__1, x, &c__1, r1, r2, w, iw, &info);
	chkxer_("DGBRFS", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 5;
	dgbrfs_("N", &c__1, &c__0, &c__0, &c_n1, a, &c__1, af, &c__1, ip, b, &
		c__1, x, &c__1, r1, r2, w, iw, &info);
	chkxer_("DGBRFS", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 7;
	dgbrfs_("N", &c__2, &c__1, &c__1, &c__1, a, &c__2, af, &c__4, ip, b, &
		c__2, x, &c__2, r1, r2, w, iw, &info);
	chkxer_("DGBRFS", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 9;
	dgbrfs_("N", &c__2, &c__1, &c__1, &c__1, a, &c__3, af, &c__3, ip, b, &
		c__2, x, &c__2, r1, r2, w, iw, &info);
	chkxer_("DGBRFS", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 12;
	dgbrfs_("N", &c__2, &c__0, &c__0, &c__1, a, &c__1, af, &c__1, ip, b, &
		c__1, x, &c__2, r1, r2, w, iw, &info);
	chkxer_("DGBRFS", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 14;
	dgbrfs_("N", &c__2, &c__0, &c__0, &c__1, a, &c__1, af, &c__1, ip, b, &
		c__2, x, &c__1, r1, r2, w, iw, &info);
	chkxer_("DGBRFS", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);

/*        DGBCON */

	s_copy(srnamc_1.srnamt, "DGBCON", (ftnlen)6, (ftnlen)6);
	infoc_1.infot = 1;
	dgbcon_("/", &c__0, &c__0, &c__0, a, &c__1, ip, &anrm, &rcond, w, iw, 
		&info);
	chkxer_("DGBCON", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 2;
	dgbcon_("1", &c_n1, &c__0, &c__0, a, &c__1, ip, &anrm, &rcond, w, iw, 
		&info);
	chkxer_("DGBCON", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 3;
	dgbcon_("1", &c__1, &c_n1, &c__0, a, &c__1, ip, &anrm, &rcond, w, iw, 
		&info);
	chkxer_("DGBCON", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 4;
	dgbcon_("1", &c__1, &c__0, &c_n1, a, &c__1, ip, &anrm, &rcond, w, iw, 
		&info);
	chkxer_("DGBCON", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 6;
	dgbcon_("1", &c__2, &c__1, &c__1, a, &c__3, ip, &anrm, &rcond, w, iw, 
		&info);
	chkxer_("DGBCON", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);

/*        DGBEQU */

	s_copy(srnamc_1.srnamt, "DGBEQU", (ftnlen)6, (ftnlen)6);
	infoc_1.infot = 1;
	dgbequ_(&c_n1, &c__0, &c__0, &c__0, a, &c__1, r1, r2, &rcond, &ccond, 
		&anrm, &info);
	chkxer_("DGBEQU", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 2;
	dgbequ_(&c__0, &c_n1, &c__0, &c__0, a, &c__1, r1, r2, &rcond, &ccond, 
		&anrm, &info);
	chkxer_("DGBEQU", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 3;
	dgbequ_(&c__1, &c__1, &c_n1, &c__0, a, &c__1, r1, r2, &rcond, &ccond, 
		&anrm, &info);
	chkxer_("DGBEQU", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 4;
	dgbequ_(&c__1, &c__1, &c__0, &c_n1, a, &c__1, r1, r2, &rcond, &ccond, 
		&anrm, &info);
	chkxer_("DGBEQU", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
	infoc_1.infot = 6;
	dgbequ_(&c__2, &c__2, &c__1, &c__1, a, &c__2, r1, r2, &rcond, &ccond, 
		&anrm, &info);
	chkxer_("DGBEQU", &infoc_1.infot, &infoc_1.nout, &infoc_1.lerr, &
		infoc_1.ok);
    }

/*     Print a summary line. */

    alaesm_(path, &infoc_1.ok, &infoc_1.nout);

    return 0;

/*     End of DERRGE */

} /* derrge_ */
예제 #2
0
/* Subroutine */ int dgbrfsx_(char *trans, char *equed, integer *n, integer *
	kl, integer *ku, integer *nrhs, doublereal *ab, integer *ldab, 
	doublereal *afb, integer *ldafb, integer *ipiv, doublereal *r__, 
	doublereal *c__, doublereal *b, integer *ldb, doublereal *x, integer *
	ldx, doublereal *rcond, doublereal *berr, integer *n_err_bnds__, 
	doublereal *err_bnds_norm__, doublereal *err_bnds_comp__, integer *
	nparams, doublereal *params, doublereal *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;
    doublereal d__1, d__2;

    /* Local variables */
    doublereal illrcond_thresh__, unstable_thresh__, err_lbnd__;
    integer ref_type__;
    integer j;
    doublereal rcond_tmp__;
    integer prec_type__, trans_type__;
    doublereal cwise_wrong__;
    char norm[1];
    logical ignore_cwise__;
    doublereal anorm;
    logical colequ, notran, rowequ;
    integer ithresh, n_norms__;
    doublereal 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.                    -- */

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

/*     DGBRFSX 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 DGETRF; for 1<=i<=N, row i of the */
/*     matrix was interchanged with row IPIV(i). */

/*     R       (input or output) DOUBLE PRECISION 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) DOUBLE PRECISION 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) DOUBLE PRECISION 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) DOUBLE PRECISION array, dimension (LDX,NRHS) */
/*     On entry, the solution matrix X, as computed by DGETRS. */
/*     On exit, the improved solution matrix X. */

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

/*     RCOND   (output) DOUBLE PRECISION */
/*     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) DOUBLE PRECISION 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) DOUBLE PRECISION 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) * dlamch('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) * dlamch('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) * dlamch('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) DOUBLE PRECISION 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) * dlamch('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) * dlamch('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) * dlamch('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) DOUBLE PRECISION 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: 1.0D+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) DOUBLE PRECISION 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. */

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

/*     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.) {
	    params[1] = 1.;
	} else {
	    ref_type__ = (integer) params[1];
	}
    }

/*     Set default parameters. */

    illrcond_thresh__ = (doublereal) (*n) * dlamch_("Epsilon");
    ithresh = 10;
    rthresh = .5;
    unstable_thresh__ = .25;
    ignore_cwise__ = FALSE_;

    if (*nparams >= 2) {
	if (params[2] < 0.) {
	    params[2] = (doublereal) ithresh;
	} else {
	    ithresh = (integer) params[2];
	}
    }
    if (*nparams >= 3) {
	if (params[3] < 0.) {
	    if (ignore_cwise__) {
		params[3] = 0.;
	    } else {
		params[3] = 1.;
	    }
	} else {
	    ignore_cwise__ = params[3] == 0.;
	}
    }
    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_("DGBRFSX", &i__1);
	return 0;
    }

/*     Quick return if possible. */

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

/*     Default to failure. */

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

/*     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 = dlangb_(norm, n, kl, ku, &ab[ab_offset], ldab, &work[1]);
    dgbcon_(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_("E");
	if (notran) {
	    dla_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 {
	    dla_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 */
    d__1 = 10., d__2 = sqrt((doublereal) (*n));
    err_lbnd__ = max(d__1,d__2) * dlamch_("Epsilon");
    if (*n_err_bnds__ >= 1 && n_norms__ >= 1) {

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

	if (colequ && notran) {
	    rcond_tmp__ = dla_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__ = dla_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__ = dla_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.) {
		err_bnds_norm__[j + (err_bnds_norm_dim1 << 1)] = 1.;
	    }

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

	    if (rcond_tmp__ < illrcond_thresh__) {
		err_bnds_norm__[j + (err_bnds_norm_dim1 << 1)] = 1.;
		err_bnds_norm__[j + err_bnds_norm_dim1] = 0.;
		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.;
	    }

/*     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(dlamch_("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__ = dla_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.;
	    }

/*     Cap the error at 1.0. */

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

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

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

/*     Save the condition number. */

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

    return 0;

/*     End of DGBRFSX */

} /* dgbrfsx_ */
예제 #3
0
/* Subroutine */ int dgbsvx_(char *fact, char *trans, integer *n, integer *kl, 
	 integer *ku, integer *nrhs, doublereal *ab, integer *ldab, 
	doublereal *afb, integer *ldafb, integer *ipiv, char *equed, 
	doublereal *r__, doublereal *c__, doublereal *b, integer *ldb, 
	doublereal *x, integer *ldx, doublereal *rcond, doublereal *ferr, 
	doublereal *berr, doublereal *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;
    doublereal d__1, d__2, d__3;

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

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

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

/*  DGBSVX 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) DOUBLE PRECISION 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) DOUBLE PRECISION 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 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.  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 DGBTRF; 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) DOUBLE PRECISION 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) DOUBLE PRECISION 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) DOUBLE PRECISION 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) DOUBLE PRECISION 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) DOUBLE PRECISION */
/*          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) DOUBLE PRECISION 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) DOUBLE PRECISION 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) DOUBLE PRECISION 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. */

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

    /* 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 = dlamch_("Safe minimum");
	bignum = 1. / 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.;
	    i__1 = *n;
	    for (j = 1; j <= i__1; ++j) {
/* Computing MIN */
		d__1 = rcmin, d__2 = r__[j];
		rcmin = min(d__1,d__2);
/* Computing MAX */
		d__1 = rcmax, d__2 = r__[j];
		rcmax = max(d__1,d__2);
	    }
	    if (rcmin <= 0.) {
		*info = -13;
	    } else if (*n > 0) {
		rowcnd = max(rcmin,smlnum) / min(rcmax,bignum);
	    } else {
		rowcnd = 1.;
	    }
	}
	if (colequ && *info == 0) {
	    rcmin = bignum;
	    rcmax = 0.;
	    i__1 = *n;
	    for (j = 1; j <= i__1; ++j) {
/* Computing MIN */
		d__1 = rcmin, d__2 = c__[j];
		rcmin = min(d__1,d__2);
/* Computing MAX */
		d__1 = rcmax, d__2 = c__[j];
		rcmax = max(d__1,d__2);
	    }
	    if (rcmin <= 0.) {
		*info = -14;
	    } else if (*n > 0) {
		colcnd = max(rcmin,smlnum) / min(rcmax,bignum);
	    } else {
		colcnd = 1.;
	    }
	}
	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_("DGBSVX", &i__1);
	return 0;
    }

    if (equil) {

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

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

/*           Equilibrate the matrix. */

	    dlaqgb_(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;
	    dcopy_(&i__2, &ab[*ku + 1 - j + j1 + j * ab_dim1], &c__1, &afb[*
		    kl + *ku + 1 - j + j1 + j * afb_dim1], &c__1);
	}

	dgbtrf_(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.;
	    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 */
		    d__2 = anorm, d__3 = (d__1 = ab[i__ + j * ab_dim1], abs(
			    d__1));
		    anorm = max(d__2,d__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 = dlantb_("M", "U", "N", info, &i__1, &afb[max(i__4, i__5)
		    + afb_dim1], ldafb, &work[1]);
	    if (rpvgrw == 0.) {
		rpvgrw = 1.;
	    } else {
		rpvgrw = anorm / rpvgrw;
	    }
	    work[1] = rpvgrw;
	    *rcond = 0.;
	    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 = dlangb_(norm, n, kl, ku, &ab[ab_offset], ldab, &work[1]);
    i__1 = *kl + *ku;
    rpvgrw = dlantb_("M", "U", "N", n, &i__1, &afb[afb_offset], ldafb, &work[
	    1]);
    if (rpvgrw == 0.) {
	rpvgrw = 1.;
    } else {
	rpvgrw = dlangb_("M", n, kl, ku, &ab[ab_offset], ldab, &work[1]) / rpvgrw;
    }

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

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

/*     Compute the solution matrix X. */

    dlacpy_("Full", n, nrhs, &b[b_offset], ldb, &x[x_offset], ldx);
    dgbtrs_(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. */

    dgbrfs_(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 < dlamch_("Epsilon")) {
	*info = *n + 1;
    }

    work[1] = rpvgrw;
    return 0;

/*     End of DGBSVX */

} /* dgbsvx_ */