/*  -- translated by f2c (version 19940927).

   You must link the resulting object file with the libraries:

	-lf2c -lm   (in that order)

*/

#include "f2c.h"

/* Table of constant values */

static integer c__3 = 3;

static integer c__1 = 1;

static real c_b8 = 1.f;

static real c_b10 = 0.f;

/* Subroutine */ int slarge_(integer *n, real *a, integer *lda, integer *

	iseed, real *work, integer *info)

{

    /* System generated locals */

    integer a_dim1, a_offset, i__1;

    real r__1;

    /* Builtin functions */

    double r_sign(real *, real *);

    /* Local variables */

    extern /* Subroutine */ int sger_(integer *, integer *, real *, real *, 

	    integer *, real *, integer *, real *, integer *);

    extern real snrm2_(integer *, real *, integer *);

    static integer i;

    extern /* Subroutine */ int sscal_(integer *, real *, real *, integer *), 

	    sgemv_(char *, integer *, integer *, real *, real *, integer *, 

	    real *, integer *, real *, real *, integer *);

    static real wa, wb, wn;

    extern /* Subroutine */ int xerbla_(char *, integer *), slarnv_(

	    integer *, integer *, integer *, real *);

    static real tau;

/*  -- LAPACK auxiliary test routine (version 2.0)   

       Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,   

       Courant Institute, Argonne National Lab, and Rice University   

       February 29, 1992   

    Purpose   

    =======   

    SLARGE pre- and post-multiplies a real general n by n matrix A   

    with a random orthogonal matrix: A = U*D*U'.   

    Arguments   

    =========   

    N       (input) INTEGER   

            The order of the matrix A.  N >= 0.   

    A       (input/output) REAL array, dimension (LDA,N)   

            On entry, the original n by n matrix A.   

            On exit, A is overwritten by U*A*U' for some random   

            orthogonal matrix U.   

    LDA     (input) INTEGER   

            The leading dimension of the array A.  LDA >= N.   

    ISEED   (input/output) INTEGER array, dimension (4)   

            On entry, the seed of the random number generator; the array 

            elements must be between 0 and 4095, and ISEED(4) must be   

            odd.   

            On exit, the seed is updated.   

    WORK    (workspace) REAL array, dimension (2*N)   

    INFO    (output) INTEGER   

            = 0: successful exit   

            < 0: if INFO = -i, the i-th argument had an illegal value   

    ===================================================================== 

       Test the input arguments   

       Parameter adjustments */

    a_dim1 = *lda;

    a_offset = a_dim1 + 1;

    a -= a_offset;

    --iseed;

    --work;

    /* Function Body */

    *info = 0;

    if (*n < 0) {

	*info = -1;

    } else if (*lda < max(1,*n)) {

	*info = -3;

    }

    if (*info < 0) {

	i__1 = -(*info);

	xerbla_("SLARGE", &i__1);

	return 0;

    }

/*     pre- and post-multiply A by random orthogonal matrix */

    for (i = *n; i >= 1; --i) {

/*        generate random reflection */

	i__1 = *n - i + 1;

	slarnv_(&c__3, &iseed[1], &i__1, &work[1]);

	i__1 = *n - i + 1;

	wn = snrm2_(&i__1, &work[1], &c__1);

	wa = r_sign(&wn, &work[1]);

	if (wn == 0.f) {

	    tau = 0.f;

	} else {

	    wb = work[1] + wa;

	    i__1 = *n - i;

	    r__1 = 1.f / wb;

	    sscal_(&i__1, &r__1, &work[2], &c__1);

	    work[1] = 1.f;

	    tau = wb / wa;

	}

/*        multiply A(i:n,1:n) by random reflection from the left */

	i__1 = *n - i + 1;

	sgemv_("Transpose", &i__1, n, &c_b8, &a[i + a_dim1], lda, &work[1], &

		c__1, &c_b10, &work[*n + 1], &c__1);

	i__1 = *n - i + 1;

	r__1 = -(doublereal)tau;

	sger_(&i__1, n, &r__1, &work[1], &c__1, &work[*n + 1], &c__1, &a[i + 

		a_dim1], lda);

/*        multiply A(1:n,i:n) by random reflection from the right */

	i__1 = *n - i + 1;

	sgemv_("No transpose", n, &i__1, &c_b8, &a[i * a_dim1 + 1], lda, &

		work[1], &c__1, &c_b10, &work[*n + 1], &c__1);

	i__1 = *n - i + 1;

	r__1 = -(doublereal)tau;

	sger_(n, &i__1, &r__1, &work[*n + 1], &c__1, &work[1], &c__1, &a[i * 

		a_dim1 + 1], lda);

/* L10: */

    }

    return 0;

/*     End of SLARGE */

} /* slarge_ */