dlakf2.c

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/* dlakf2.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 doublereal c_b3 = 0.;

/* Subroutine */ int dlakf2_(integer *m, integer *n, doublereal *a, integer *
        lda, doublereal *b, doublereal *d__, doublereal *e, doublereal *z__, 
        integer *ldz)
{
    /* System generated locals */
    integer a_dim1, a_offset, b_dim1, b_offset, d_dim1, d_offset, e_dim1, 
            e_offset, z_dim1, z_offset, i__1, i__2, i__3;

    /* Local variables */
    integer i__, j, l, ik, jk, mn, mn2;
    extern /* Subroutine */ int dlaset_(char *, integer *, integer *, 
            doublereal *, doublereal *, doublereal *, integer *);


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

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

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

/*  Form the 2*M*N by 2*M*N matrix */

/*         Z = [ kron(In, A)  -kron(B', Im) ] */
/*             [ kron(In, D)  -kron(E', Im) ], */

/*  where In is the identity matrix of size n and X' is the transpose */
/*  of X. kron(X, Y) is the Kronecker product between the matrices X */
/*  and Y. */

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

/*  M       (input) INTEGER */
/*          Size of matrix, must be >= 1. */

/*  N       (input) INTEGER */
/*          Size of matrix, must be >= 1. */

/*  A       (input) DOUBLE PRECISION, dimension ( LDA, M ) */
/*          The matrix A in the output matrix Z. */

/*  LDA     (input) INTEGER */
/*          The leading dimension of A, B, D, and E. ( LDA >= M+N ) */

/*  B       (input) DOUBLE PRECISION, dimension ( LDA, N ) */
/*  D       (input) DOUBLE PRECISION, dimension ( LDA, M ) */
/*  E       (input) DOUBLE PRECISION, dimension ( LDA, N ) */
/*          The matrices used in forming the output matrix Z. */

/*  Z       (output) DOUBLE PRECISION, dimension ( LDZ, 2*M*N ) */
/*          The resultant Kronecker M*N*2 by M*N*2 matrix (see above.) */

/*  LDZ     (input) INTEGER */
/*          The leading dimension of Z. ( LDZ >= 2*M*N ) */

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

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

/*     Initialize Z */

    /* Parameter adjustments */
    e_dim1 = *lda;
    e_offset = 1 + e_dim1;
    e -= e_offset;
    d_dim1 = *lda;
    d_offset = 1 + d_dim1;
    d__ -= d_offset;
    b_dim1 = *lda;
    b_offset = 1 + b_dim1;
    b -= b_offset;
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    z_dim1 = *ldz;
    z_offset = 1 + z_dim1;
    z__ -= z_offset;

    /* Function Body */
    mn = *m * *n;
    mn2 = mn << 1;
    dlaset_("Full", &mn2, &mn2, &c_b3, &c_b3, &z__[z_offset], ldz);

    ik = 1;
    i__1 = *n;
    for (l = 1; l <= i__1; ++l) {

/*        form kron(In, A) */

        i__2 = *m;
        for (i__ = 1; i__ <= i__2; ++i__) {
            i__3 = *m;
            for (j = 1; j <= i__3; ++j) {
                z__[ik + i__ - 1 + (ik + j - 1) * z_dim1] = a[i__ + j * 
                        a_dim1];
/* L10: */
            }
/* L20: */
        }

/*        form kron(In, D) */

        i__2 = *m;
        for (i__ = 1; i__ <= i__2; ++i__) {
            i__3 = *m;
            for (j = 1; j <= i__3; ++j) {
                z__[ik + mn + i__ - 1 + (ik + j - 1) * z_dim1] = d__[i__ + j *
                         d_dim1];
/* L30: */
            }
/* L40: */
        }

        ik += *m;
/* L50: */
    }

    ik = 1;
    i__1 = *n;
    for (l = 1; l <= i__1; ++l) {
        jk = mn + 1;

        i__2 = *n;
        for (j = 1; j <= i__2; ++j) {

/*           form -kron(B', Im) */

            i__3 = *m;
            for (i__ = 1; i__ <= i__3; ++i__) {
                z__[ik + i__ - 1 + (jk + i__ - 1) * z_dim1] = -b[j + l * 
                        b_dim1];
/* L60: */
            }

/*           form -kron(E', Im) */

            i__3 = *m;
            for (i__ = 1; i__ <= i__3; ++i__) {
                z__[ik + mn + i__ - 1 + (jk + i__ - 1) * z_dim1] = -e[j + l * 
                        e_dim1];
/* L70: */
            }

            jk += *m;
/* L80: */
        }

        ik += *m;
/* L90: */
    }

    return 0;

/*     End of DLAKF2 */

} /* dlakf2_ */