/* sqrt15.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__16 = 16;
static integer c__2 = 2;
static integer c__1 = 1;
static real c_b18 = 0.f;
static real c_b19 = 1.f;
static real c_b22 = 2.f;
static integer c__0 = 0;
/* Subroutine */ int sqrt15_(integer *scale, integer *rksel, integer *m,
integer *n, integer *nrhs, real *a, integer *lda, real *b, integer *
ldb, real *s, integer *rank, real *norma, real *normb, integer *iseed,
real *work, integer *lwork)
{
/* System generated locals */
integer a_dim1, a_offset, b_dim1, b_offset, i__1, i__2;
real r__1;
/* Local variables */
integer j, mn;
real eps;
integer info;
real temp;
extern doublereal snrm2_(integer *, real *, integer *);
extern /* Subroutine */ int sscal_(integer *, real *, real *, integer *),
slarf_(char *, integer *, integer *, real *, integer *, real *,
real *, integer *, real *), sgemm_(char *, char *,
integer *, integer *, integer *, real *, real *, integer *, real *
, integer *, real *, real *, integer *);
extern doublereal sasum_(integer *, real *, integer *);
real dummy[1];
extern doublereal slamch_(char *), slange_(char *, integer *,
integer *, real *, integer *, real *);
extern /* Subroutine */ int xerbla_(char *, integer *);
real bignum;
extern /* Subroutine */ int slascl_(char *, integer *, integer *, real *,
real *, integer *, integer *, real *, integer *, integer *);
extern doublereal slarnd_(integer *, integer *);
extern /* Subroutine */ int slaord_(char *, integer *, real *, integer *), slaset_(char *, integer *, integer *, real *, real *,
real *, integer *), slaror_(char *, char *, integer *,
integer *, real *, integer *, integer *, real *, integer *), slarnv_(integer *, integer *, integer *, real *);
real smlnum;
/* -- LAPACK test routine (version 3.1) -- */
/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/* November 2006 */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* Purpose */
/* ======= */
/* SQRT15 generates a matrix with full or deficient rank and of various */
/* norms. */
/* Arguments */
/* ========= */
/* SCALE (input) INTEGER */
/* SCALE = 1: normally scaled matrix */
/* SCALE = 2: matrix scaled up */
/* SCALE = 3: matrix scaled down */
/* RKSEL (input) INTEGER */
/* RKSEL = 1: full rank matrix */
/* RKSEL = 2: rank-deficient matrix */
/* M (input) INTEGER */
/* The number of rows of the matrix A. */
/* N (input) INTEGER */
/* The number of columns of A. */
/* NRHS (input) INTEGER */
/* The number of columns of B. */
/* A (output) REAL array, dimension (LDA,N) */
/* The M-by-N matrix A. */
/* LDA (input) INTEGER */
/* The leading dimension of the array A. */
/* B (output) REAL array, dimension (LDB, NRHS) */
/* A matrix that is in the range space of matrix A. */
/* LDB (input) INTEGER */
/* The leading dimension of the array B. */
/* S (output) REAL array, dimension MIN(M,N) */
/* Singular values of A. */
/* RANK (output) INTEGER */
/* number of nonzero singular values of A. */
/* NORMA (output) REAL */
/* one-norm of A. */
/* NORMB (output) REAL */
/* one-norm of B. */
/* ISEED (input/output) integer array, dimension (4) */
/* seed for random number generator. */
/* WORK (workspace) REAL array, dimension (LWORK) */
/* LWORK (input) INTEGER */
/* length of work space required. */
/* LWORK >= MAX(M+MIN(M,N),NRHS*MIN(M,N),2*N+M) */
/* ===================================================================== */
/* .. Parameters .. */
/* .. */
/* .. Local Scalars .. */
/* .. */
/* .. Local Arrays .. */
/* .. */
/* .. External Functions .. */
/* .. */
/* .. External Subroutines .. */
/* .. */
/* .. Intrinsic Functions .. */
/* .. */
/* .. Executable Statements .. */
/* Parameter adjustments */
a_dim1 = *lda;
a_offset = 1 + a_dim1;
a -= a_offset;
b_dim1 = *ldb;
b_offset = 1 + b_dim1;
b -= b_offset;
--s;
--iseed;
--work;
/* Function Body */
mn = min(*m,*n);
/* Computing MAX */
i__1 = *m + mn, i__2 = mn * *nrhs, i__1 = max(i__1,i__2), i__2 = (*n << 1)
+ *m;
if (*lwork < max(i__1,i__2)) {
xerbla_("SQRT15", &c__16);
return 0;
}
smlnum = slamch_("Safe minimum");
bignum = 1.f / smlnum;
eps = slamch_("Epsilon");
smlnum = smlnum / eps / eps;
bignum = 1.f / smlnum;
/* Determine rank and (unscaled) singular values */
if (*rksel == 1) {
*rank = mn;
} else if (*rksel == 2) {
*rank = mn * 3 / 4;
i__1 = mn;
for (j = *rank + 1; j <= i__1; ++j) {
s[j] = 0.f;
/* L10: */
}
} else {
xerbla_("SQRT15", &c__2);
}
if (*rank > 0) {
/* Nontrivial case */
s[1] = 1.f;
i__1 = *rank;
for (j = 2; j <= i__1; ++j) {
L20:
temp = slarnd_(&c__1, &iseed[1]);
if (temp > .1f) {
s[j] = dabs(temp);
} else {
goto L20;
}
/* L30: */
}
slaord_("Decreasing", rank, &s[1], &c__1);
/* Generate 'rank' columns of a random orthogonal matrix in A */
slarnv_(&c__2, &iseed[1], m, &work[1]);
r__1 = 1.f / snrm2_(m, &work[1], &c__1);
sscal_(m, &r__1, &work[1], &c__1);
slaset_("Full", m, rank, &c_b18, &c_b19, &a[a_offset], lda)
;
slarf_("Left", m, rank, &work[1], &c__1, &c_b22, &a[a_offset], lda, &
work[*m + 1]);
/* workspace used: m+mn */
/* Generate consistent rhs in the range space of A */
i__1 = *rank * *nrhs;
slarnv_(&c__2, &iseed[1], &i__1, &work[1]);
sgemm_("No transpose", "No transpose", m, nrhs, rank, &c_b19, &a[
a_offset], lda, &work[1], rank, &c_b18, &b[b_offset], ldb);
/* work space used: <= mn *nrhs */
/* generate (unscaled) matrix A */
i__1 = *rank;
for (j = 1; j <= i__1; ++j) {
sscal_(m, &s[j], &a[j * a_dim1 + 1], &c__1);
/* L40: */
}
if (*rank < *n) {
i__1 = *n - *rank;
slaset_("Full", m, &i__1, &c_b18, &c_b18, &a[(*rank + 1) * a_dim1
+ 1], lda);
}
slaror_("Right", "No initialization", m, n, &a[a_offset], lda, &iseed[
1], &work[1], &info);
} else {
/* work space used 2*n+m */
/* Generate null matrix and rhs */
i__1 = mn;
for (j = 1; j <= i__1; ++j) {
s[j] = 0.f;
/* L50: */
}
slaset_("Full", m, n, &c_b18, &c_b18, &a[a_offset], lda);
slaset_("Full", m, nrhs, &c_b18, &c_b18, &b[b_offset], ldb)
;
}
/* Scale the matrix */
if (*scale != 1) {
*norma = slange_("Max", m, n, &a[a_offset], lda, dummy);
if (*norma != 0.f) {
if (*scale == 2) {
/* matrix scaled up */
slascl_("General", &c__0, &c__0, norma, &bignum, m, n, &a[
a_offset], lda, &info);
slascl_("General", &c__0, &c__0, norma, &bignum, &mn, &c__1, &
s[1], &mn, &info);
slascl_("General", &c__0, &c__0, norma, &bignum, m, nrhs, &b[
b_offset], ldb, &info);
} else if (*scale == 3) {
/* matrix scaled down */
slascl_("General", &c__0, &c__0, norma, &smlnum, m, n, &a[
a_offset], lda, &info);
slascl_("General", &c__0, &c__0, norma, &smlnum, &mn, &c__1, &
s[1], &mn, &info);
slascl_("General", &c__0, &c__0, norma, &smlnum, m, nrhs, &b[
b_offset], ldb, &info);
} else {
xerbla_("SQRT15", &c__1);
return 0;
}
}
}
*norma = sasum_(&mn, &s[1], &c__1);
*normb = slange_("One-norm", m, nrhs, &b[b_offset], ldb, dummy)
;
return 0;
/* End of SQRT15 */
} /* sqrt15_ */