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authorshmel1k <shmel1k@ydb.tech>2022-09-02 12:44:59 +0300
committershmel1k <shmel1k@ydb.tech>2022-09-02 12:44:59 +0300
commit90d450f74722da7859d6f510a869f6c6908fd12f (patch)
tree538c718dedc76cdfe37ad6d01ff250dd930d9278 /contrib/libs/clapack/sgerq2.c
parent01f64c1ecd0d4ffa9e3a74478335f1745f26cc75 (diff)
downloadydb-90d450f74722da7859d6f510a869f6c6908fd12f.tar.gz
[] add metering mode to CLI
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+/* sgerq2.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"
+
+/* Subroutine */ int sgerq2_(integer *m, integer *n, real *a, integer *lda,
+ real *tau, real *work, integer *info)
+{
+ /* System generated locals */
+ integer a_dim1, a_offset, i__1, i__2;
+
+ /* Local variables */
+ integer i__, k;
+ real aii;
+ extern /* Subroutine */ int slarf_(char *, integer *, integer *, real *,
+ integer *, real *, real *, integer *, real *), xerbla_(
+ char *, integer *), slarfp_(integer *, real *, real *,
+ integer *, real *);
+
+
+/* -- LAPACK routine (version 3.2) -- */
+/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
+/* November 2006 */
+
+/* .. Scalar Arguments .. */
+/* .. */
+/* .. Array Arguments .. */
+/* .. */
+
+/* Purpose */
+/* ======= */
+
+/* SGERQ2 computes an RQ factorization of a real m by n matrix A: */
+/* A = R * Q. */
+
+/* Arguments */
+/* ========= */
+
+/* M (input) INTEGER */
+/* The number of rows of the matrix A. M >= 0. */
+
+/* N (input) INTEGER */
+/* The number of columns of the matrix A. N >= 0. */
+
+/* A (input/output) REAL array, dimension (LDA,N) */
+/* On entry, the m by n matrix A. */
+/* On exit, if m <= n, the upper triangle of the subarray */
+/* A(1:m,n-m+1:n) contains the m by m upper triangular matrix R; */
+/* if m >= n, the elements on and above the (m-n)-th subdiagonal */
+/* contain the m by n upper trapezoidal matrix R; the remaining */
+/* elements, with the array TAU, represent the orthogonal matrix */
+/* Q as a product of elementary reflectors (see Further */
+/* Details). */
+
+/* LDA (input) INTEGER */
+/* The leading dimension of the array A. LDA >= max(1,M). */
+
+/* TAU (output) REAL array, dimension (min(M,N)) */
+/* The scalar factors of the elementary reflectors (see Further */
+/* Details). */
+
+/* WORK (workspace) REAL array, dimension (M) */
+
+/* INFO (output) INTEGER */
+/* = 0: successful exit */
+/* < 0: if INFO = -i, the i-th argument had an illegal value */
+
+/* Further Details */
+/* =============== */
+
+/* The matrix Q is represented as a product of elementary reflectors */
+
+/* Q = H(1) H(2) . . . H(k), where k = min(m,n). */
+
+/* Each H(i) has the form */
+
+/* H(i) = I - tau * v * v' */
+
+/* where tau is a real scalar, and v is a real vector with */
+/* v(n-k+i+1:n) = 0 and v(n-k+i) = 1; v(1:n-k+i-1) is stored on exit in */
+/* A(m-k+i,1:n-k+i-1), and tau in TAU(i). */
+
+/* ===================================================================== */
+
+/* .. Parameters .. */
+/* .. */
+/* .. Local Scalars .. */
+/* .. */
+/* .. External Subroutines .. */
+/* .. */
+/* .. Intrinsic Functions .. */
+/* .. */
+/* .. Executable Statements .. */
+
+/* Test the input arguments */
+
+ /* Parameter adjustments */
+ a_dim1 = *lda;
+ a_offset = 1 + a_dim1;
+ a -= a_offset;
+ --tau;
+ --work;
+
+ /* Function Body */
+ *info = 0;
+ if (*m < 0) {
+ *info = -1;
+ } else if (*n < 0) {
+ *info = -2;
+ } else if (*lda < max(1,*m)) {
+ *info = -4;
+ }
+ if (*info != 0) {
+ i__1 = -(*info);
+ xerbla_("SGERQ2", &i__1);
+ return 0;
+ }
+
+ k = min(*m,*n);
+
+ for (i__ = k; i__ >= 1; --i__) {
+
+/* Generate elementary reflector H(i) to annihilate */
+/* A(m-k+i,1:n-k+i-1) */
+
+ i__1 = *n - k + i__;
+ slarfp_(&i__1, &a[*m - k + i__ + (*n - k + i__) * a_dim1], &a[*m - k
+ + i__ + a_dim1], lda, &tau[i__]);
+
+/* Apply H(i) to A(1:m-k+i-1,1:n-k+i) from the right */
+
+ aii = a[*m - k + i__ + (*n - k + i__) * a_dim1];
+ a[*m - k + i__ + (*n - k + i__) * a_dim1] = 1.f;
+ i__1 = *m - k + i__ - 1;
+ i__2 = *n - k + i__;
+ slarf_("Right", &i__1, &i__2, &a[*m - k + i__ + a_dim1], lda, &tau[
+ i__], &a[a_offset], lda, &work[1]);
+ a[*m - k + i__ + (*n - k + i__) * a_dim1] = aii;
+/* L10: */
+ }
+ return 0;
+
+/* End of SGERQ2 */
+
+} /* sgerq2_ */