sget35.c

Go to the documentation of this file.

/* sget35.f -- translated by f2c (version 20061008).
   You must link the resulting object file with libf2c:
        on Microsoft Windows system, link with libf2c.lib;
        on Linux or Unix systems, link with .../path/to/libf2c.a -lm
        or, if you install libf2c.a in a standard place, with -lf2c -lm
        -- in that order, at the end of the command line, as in
                cc *.o -lf2c -lm
        Source for libf2c is in /netlib/f2c/libf2c.zip, e.g.,

                http://www.netlib.org/f2c/libf2c.zip
*/

#include "f2c.h"
#include "blaswrap.h"

/* Table of constant values */

static integer c__6 = 6;
static real c_b35 = 1.f;

/* Subroutine */ int sget35_(real *rmax, integer *lmax, integer *ninfo, 
        integer *knt)
{
    /* Initialized data */

    static integer idim[8] = { 1,2,3,4,3,3,6,4 };
    static integer ival[288]    /* was [6][6][8] */ = { 1,0,0,0,0,0,0,0,0,0,0,
            0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,2,0,0,0,0,-2,
            0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,
            0,0,5,1,2,0,0,0,-8,-2,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
            3,4,0,0,0,0,-5,3,0,0,0,0,1,2,1,4,0,0,-3,-9,-1,1,0,0,0,0,0,0,0,0,0,
            0,0,0,0,0,1,0,0,0,0,0,2,3,0,0,0,0,5,6,7,0,0,0,0,0,0,0,0,0,0,0,0,0,
            0,0,0,0,0,0,0,0,1,0,0,0,0,0,1,3,-4,0,0,0,2,5,2,0,0,0,0,0,0,0,0,0,
            0,0,0,0,0,0,0,0,0,0,0,0,1,2,0,0,0,0,-2,0,0,0,0,0,5,6,3,4,0,0,-1,
            -9,-5,2,0,0,8,8,8,8,5,6,9,9,9,9,-7,5,1,0,0,0,0,0,1,5,2,0,0,0,2,
            -21,5,0,0,0,1,2,3,4,0,0,0,0,0,0,0,0,0,0,0,0,0,0 };

    /* System generated locals */
    integer i__1, i__2, i__3;
    real r__1, r__2, r__3;

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

    /* Local variables */
    real a[36]  /* was [6][6] */, b[36] /* was [6][6] */, c__[36]       /* 
            was [6][6] */;
    integer i__, j, m, n;
    real cc[36] /* was [6][6] */, vm1[3], vm2[3];
    integer ima, imb;
    real dum[1], eps, res, res1;
    integer info;
    real cnrm;
    integer isgn;
    real rmul, tnrm, xnrm, scale;
    char trana[1], tranb[1];
    extern /* Subroutine */ int sgemm_(char *, char *, integer *, integer *, 
            integer *, real *, real *, integer *, real *, integer *, real *, 
            real *, integer *);
    integer imlda1, imlda2, imldb1;
    extern /* Subroutine */ int slabad_(real *, real *);
    extern doublereal slamch_(char *), slange_(char *, integer *, 
            integer *, real *, integer *, real *);
    integer imloff, itrana, itranb;
    real bignum, smlnum;
    extern /* Subroutine */ int strsyl_(char *, char *, integer *, integer *, 
            integer *, real *, integer *, real *, integer *, real *, integer *
, real *, integer *);


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

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

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

/*  SGET35 tests STRSYL, a routine for solving the Sylvester matrix */
/*  equation */

/*     op(A)*X + ISGN*X*op(B) = scale*C, */

/*  A and B are assumed to be in Schur canonical form, op() represents an */
/*  optional transpose, and ISGN can be -1 or +1.  Scale is an output */
/*  less than or equal to 1, chosen to avoid overflow in X. */

/*  The test code verifies that the following residual is order 1: */

/*     norm(op(A)*X + ISGN*X*op(B) - scale*C) / */
/*         (EPS*max(norm(A),norm(B))*norm(X)) */

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

/*  RMAX    (output) REAL */
/*          Value of the largest test ratio. */

/*  LMAX    (output) INTEGER */
/*          Example number where largest test ratio achieved. */

/*  NINFO   (output) INTEGER */
/*          Number of examples where INFO is nonzero. */

/*  KNT     (output) INTEGER */
/*          Total number of examples tested. */

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

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

/*     Get machine parameters */

    eps = slamch_("P");
    smlnum = slamch_("S") * 4.f / eps;
    bignum = 1.f / smlnum;
    slabad_(&smlnum, &bignum);

/*     Set up test case parameters */

    vm1[0] = sqrt(smlnum);
    vm1[1] = 1.f;
    vm1[2] = sqrt(bignum);
    vm2[0] = 1.f;
    vm2[1] = eps * 2.f + 1.f;
    vm2[2] = 2.f;

    *knt = 0;
    *ninfo = 0;
    *lmax = 0;
    *rmax = 0.f;

/*     Begin test loop */

    for (itrana = 1; itrana <= 2; ++itrana) {
        for (itranb = 1; itranb <= 2; ++itranb) {
            for (isgn = -1; isgn <= 1; isgn += 2) {
                for (ima = 1; ima <= 8; ++ima) {
                    for (imlda1 = 1; imlda1 <= 3; ++imlda1) {
                        for (imlda2 = 1; imlda2 <= 3; ++imlda2) {
                            for (imloff = 1; imloff <= 2; ++imloff) {
                                for (imb = 1; imb <= 8; ++imb) {
                                    for (imldb1 = 1; imldb1 <= 3; ++imldb1) {
                                        if (itrana == 1) {
                                            *(unsigned char *)trana = 'N';
                                        }
                                        if (itrana == 2) {
                                            *(unsigned char *)trana = 'T';
                                        }
                                        if (itranb == 1) {
                                            *(unsigned char *)tranb = 'N';
                                        }
                                        if (itranb == 2) {
                                            *(unsigned char *)tranb = 'T';
                                        }
                                        m = idim[ima - 1];
                                        n = idim[imb - 1];
                                        tnrm = 0.f;
                                        i__1 = m;
                                        for (i__ = 1; i__ <= i__1; ++i__) {
                                            i__2 = m;
                                            for (j = 1; j <= i__2; ++j) {
                          a[i__ + j * 6 - 7] = (real) ival[i__ + (j + ima * 6)
                                   * 6 - 43];
                          if ((i__3 = i__ - j, abs(i__3)) <= 1) {
                              a[i__ + j * 6 - 7] *= vm1[imlda1 - 1];
                              a[i__ + j * 6 - 7] *= vm2[imlda2 - 1];
                          } else {
                              a[i__ + j * 6 - 7] *= vm1[imloff - 1];
                          }
/* Computing MAX */
                          r__2 = tnrm, r__3 = (r__1 = a[i__ + j * 6 - 7], 
                                  dabs(r__1));
                          tnrm = dmax(r__2,r__3);
/* L10: */
                                            }
/* L20: */
                                        }
                                        i__1 = n;
                                        for (i__ = 1; i__ <= i__1; ++i__) {
                                            i__2 = n;
                                            for (j = 1; j <= i__2; ++j) {
                          b[i__ + j * 6 - 7] = (real) ival[i__ + (j + imb * 6)
                                   * 6 - 43];
                          if ((i__3 = i__ - j, abs(i__3)) <= 1) {
                              b[i__ + j * 6 - 7] *= vm1[imldb1 - 1];
                          } else {
                              b[i__ + j * 6 - 7] *= vm1[imloff - 1];
                          }
/* Computing MAX */
                          r__2 = tnrm, r__3 = (r__1 = b[i__ + j * 6 - 7], 
                                  dabs(r__1));
                          tnrm = dmax(r__2,r__3);
/* L30: */
                                            }
/* L40: */
                                        }
                                        cnrm = 0.f;
                                        i__1 = m;
                                        for (i__ = 1; i__ <= i__1; ++i__) {
                                            i__2 = n;
                                            for (j = 1; j <= i__2; ++j) {
                          c__[i__ + j * 6 - 7] = sin((real) (i__ * j));
/* Computing MAX */
                          r__1 = cnrm, r__2 = c__[i__ + j * 6 - 7];
                          cnrm = dmax(r__1,r__2);
                          cc[i__ + j * 6 - 7] = c__[i__ + j * 6 - 7];
/* L50: */
                                            }
/* L60: */
                                        }
                                        ++(*knt);
                                        strsyl_(trana, tranb, &isgn, &m, &n, 
                                                a, &c__6, b, &c__6, c__, &
                                                c__6, &scale, &info);
                                        if (info != 0) {
                                            ++(*ninfo);
                                        }
                                        xnrm = slange_("M", &m, &n, c__, &
                                                c__6, dum);
                                        rmul = 1.f;
                                        if (xnrm > 1.f && tnrm > 1.f) {
                                            if (xnrm > bignum / tnrm) {
                          rmul = 1.f / dmax(xnrm,tnrm);
                                            }
                                        }
                                        r__1 = -scale * rmul;
                                        sgemm_(trana, "N", &m, &n, &m, &rmul, 
                                                a, &c__6, c__, &c__6, &r__1, 
                                                cc, &c__6);
                                        r__1 = (real) isgn * rmul;
                                        sgemm_("N", tranb, &m, &n, &n, &r__1, 
                                                c__, &c__6, b, &c__6, &c_b35, 
                                                cc, &c__6);
                                        res1 = slange_("M", &m, &n, cc, &c__6, 
                                                 dum);
/* Computing MAX */
                                        r__1 = smlnum, r__2 = smlnum * xnrm, 
                                                r__1 = max(r__1,r__2), r__2 = 
                                                rmul * tnrm * eps * xnrm;
                                        res = res1 / dmax(r__1,r__2);
                                        if (res > *rmax) {
                                            *lmax = *knt;
                                            *rmax = res;
                                        }
/* L70: */
                                    }
/* L80: */
                                }
/* L90: */
                            }
/* L100: */
                        }
/* L110: */
                    }
/* L120: */
                }
/* L130: */
            }
/* L140: */
        }
/* L150: */
    }

    return 0;

/*     End of SGET35 */

} /* sget35_ */