181 lines
4.9 KiB
C
181 lines
4.9 KiB
C
/* slauu2.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 "clapack.h"
|
|
|
|
|
|
/* Table of constant values */
|
|
|
|
static real c_b7 = 1.f;
|
|
static integer c__1 = 1;
|
|
|
|
/* Subroutine */ int slauu2_(char *uplo, integer *n, real *a, integer *lda,
|
|
integer *info)
|
|
{
|
|
/* System generated locals */
|
|
integer a_dim1, a_offset, i__1, i__2, i__3;
|
|
|
|
/* Local variables */
|
|
integer i__;
|
|
real aii;
|
|
extern doublereal sdot_(integer *, real *, integer *, real *, integer *);
|
|
extern logical lsame_(char *, char *);
|
|
extern /* Subroutine */ int sscal_(integer *, real *, real *, integer *),
|
|
sgemv_(char *, integer *, integer *, real *, real *, integer *,
|
|
real *, integer *, real *, real *, integer *);
|
|
logical upper;
|
|
extern /* Subroutine */ int xerbla_(char *, integer *);
|
|
|
|
|
|
/* -- LAPACK auxiliary routine (version 3.2) -- */
|
|
/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
|
|
/* November 2006 */
|
|
|
|
/* .. Scalar Arguments .. */
|
|
/* .. */
|
|
/* .. Array Arguments .. */
|
|
/* .. */
|
|
|
|
/* Purpose */
|
|
/* ======= */
|
|
|
|
/* SLAUU2 computes the product U * U' or L' * L, where the triangular */
|
|
/* factor U or L is stored in the upper or lower triangular part of */
|
|
/* the array A. */
|
|
|
|
/* If UPLO = 'U' or 'u' then the upper triangle of the result is stored, */
|
|
/* overwriting the factor U in A. */
|
|
/* If UPLO = 'L' or 'l' then the lower triangle of the result is stored, */
|
|
/* overwriting the factor L in A. */
|
|
|
|
/* This is the unblocked form of the algorithm, calling Level 2 BLAS. */
|
|
|
|
/* Arguments */
|
|
/* ========= */
|
|
|
|
/* UPLO (input) CHARACTER*1 */
|
|
/* Specifies whether the triangular factor stored in the array A */
|
|
/* is upper or lower triangular: */
|
|
/* = 'U': Upper triangular */
|
|
/* = 'L': Lower triangular */
|
|
|
|
/* N (input) INTEGER */
|
|
/* The order of the triangular factor U or L. N >= 0. */
|
|
|
|
/* A (input/output) REAL array, dimension (LDA,N) */
|
|
/* On entry, the triangular factor U or L. */
|
|
/* On exit, if UPLO = 'U', the upper triangle of A is */
|
|
/* overwritten with the upper triangle of the product U * U'; */
|
|
/* if UPLO = 'L', the lower triangle of A is overwritten with */
|
|
/* the lower triangle of the product L' * L. */
|
|
|
|
/* LDA (input) INTEGER */
|
|
/* The leading dimension of the array A. LDA >= max(1,N). */
|
|
|
|
/* INFO (output) INTEGER */
|
|
/* = 0: successful exit */
|
|
/* < 0: if INFO = -k, the k-th argument had an illegal value */
|
|
|
|
/* ===================================================================== */
|
|
|
|
/* .. Parameters .. */
|
|
/* .. */
|
|
/* .. Local Scalars .. */
|
|
/* .. */
|
|
/* .. External Functions .. */
|
|
/* .. */
|
|
/* .. External Subroutines .. */
|
|
/* .. */
|
|
/* .. Intrinsic Functions .. */
|
|
/* .. */
|
|
/* .. Executable Statements .. */
|
|
|
|
/* Test the input parameters. */
|
|
|
|
/* Parameter adjustments */
|
|
a_dim1 = *lda;
|
|
a_offset = 1 + a_dim1;
|
|
a -= a_offset;
|
|
|
|
/* Function Body */
|
|
*info = 0;
|
|
upper = lsame_(uplo, "U");
|
|
if (! upper && ! lsame_(uplo, "L")) {
|
|
*info = -1;
|
|
} else if (*n < 0) {
|
|
*info = -2;
|
|
} else if (*lda < max(1,*n)) {
|
|
*info = -4;
|
|
}
|
|
if (*info != 0) {
|
|
i__1 = -(*info);
|
|
xerbla_("SLAUU2", &i__1);
|
|
return 0;
|
|
}
|
|
|
|
/* Quick return if possible */
|
|
|
|
if (*n == 0) {
|
|
return 0;
|
|
}
|
|
|
|
if (upper) {
|
|
|
|
/* Compute the product U * U'. */
|
|
|
|
i__1 = *n;
|
|
for (i__ = 1; i__ <= i__1; ++i__) {
|
|
aii = a[i__ + i__ * a_dim1];
|
|
if (i__ < *n) {
|
|
i__2 = *n - i__ + 1;
|
|
a[i__ + i__ * a_dim1] = sdot_(&i__2, &a[i__ + i__ * a_dim1],
|
|
lda, &a[i__ + i__ * a_dim1], lda);
|
|
i__2 = i__ - 1;
|
|
i__3 = *n - i__;
|
|
sgemv_("No transpose", &i__2, &i__3, &c_b7, &a[(i__ + 1) *
|
|
a_dim1 + 1], lda, &a[i__ + (i__ + 1) * a_dim1], lda, &
|
|
aii, &a[i__ * a_dim1 + 1], &c__1);
|
|
} else {
|
|
sscal_(&i__, &aii, &a[i__ * a_dim1 + 1], &c__1);
|
|
}
|
|
/* L10: */
|
|
}
|
|
|
|
} else {
|
|
|
|
/* Compute the product L' * L. */
|
|
|
|
i__1 = *n;
|
|
for (i__ = 1; i__ <= i__1; ++i__) {
|
|
aii = a[i__ + i__ * a_dim1];
|
|
if (i__ < *n) {
|
|
i__2 = *n - i__ + 1;
|
|
a[i__ + i__ * a_dim1] = sdot_(&i__2, &a[i__ + i__ * a_dim1], &
|
|
c__1, &a[i__ + i__ * a_dim1], &c__1);
|
|
i__2 = *n - i__;
|
|
i__3 = i__ - 1;
|
|
sgemv_("Transpose", &i__2, &i__3, &c_b7, &a[i__ + 1 + a_dim1],
|
|
lda, &a[i__ + 1 + i__ * a_dim1], &c__1, &aii, &a[i__
|
|
+ a_dim1], lda);
|
|
} else {
|
|
sscal_(&i__, &aii, &a[i__ + a_dim1], lda);
|
|
}
|
|
/* L20: */
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
|
|
/* End of SLAUU2 */
|
|
|
|
} /* slauu2_ */
|