sorgql(3P) Sun Performance Library sorgql(3P)NAMEsorgql - generate an M-by-N real matrix Q with orthonormal columns,
SYNOPSIS
SUBROUTINE SORGQL(M, N, K, A, LDA, TAU, WORK, LDWORK, INFO)
INTEGER M, N, K, LDA, LDWORK, INFO
REAL A(LDA,*), TAU(*), WORK(*)
SUBROUTINE SORGQL_64(M, N, K, A, LDA, TAU, WORK, LDWORK, INFO)
INTEGER*8 M, N, K, LDA, LDWORK, INFO
REAL A(LDA,*), TAU(*), WORK(*)
F95 INTERFACE
SUBROUTINE ORGQL(M, [N], [K], A, [LDA], TAU, [WORK], [LDWORK], [INFO])
INTEGER :: M, N, K, LDA, LDWORK, INFO
REAL, DIMENSION(:) :: TAU, WORK
REAL, DIMENSION(:,:) :: A
SUBROUTINE ORGQL_64(M, [N], [K], A, [LDA], TAU, [WORK], [LDWORK],
[INFO])
INTEGER(8) :: M, N, K, LDA, LDWORK, INFO
REAL, DIMENSION(:) :: TAU, WORK
REAL, DIMENSION(:,:) :: A
C INTERFACE
#include <sunperf.h>
void sorgql(int m, int n, int k, float *a, int lda, float *tau, int
*info);
void sorgql_64(long m, long n, long k, float *a, long lda, float *tau,
long *info);
PURPOSEsorgql generates an M-by-N real matrix Q with orthonormal columns,
which is defined as the last N columns of a product of K elementary
reflectors of order M
Q = H(k) . . . H(2)H(1)
as returned by SGEQLF.
ARGUMENTS
M (input) The number of rows of the matrix Q. M >= 0.
N (input) The number of columns of the matrix Q. M >= N >= 0.
K (input) The number of elementary reflectors whose product defines the
matrix Q. N >= K >= 0.
A (input/output)
On entry, the (n-k+i)-th column must contain the vector which
defines the elementary reflector H(i), for i = 1,2,...,k, as
returned by SGEQLF in the last k columns of its array argu‐
ment A. On exit, the M-by-N matrix Q.
LDA (input)
The first dimension of the array A. LDA >= max(1,M).
TAU (input)
TAU(i) must contain the scalar factor of the elementary
reflector H(i), as returned by SGEQLF.
WORK (workspace)
On exit, if INFO = 0, WORK(1) returns the optimal LDWORK.
LDWORK (input)
The dimension of the array WORK. LDWORK >= max(1,N). For
optimum performance LDWORK >= N*NB, where NB is the optimal
blocksize.
If LDWORK = -1, then a workspace query is assumed; the rou‐
tine only calculates the optimal size of the WORK array,
returns this value as the first entry of the WORK array, and
no error message related to LDWORK is issued by XERBLA.
INFO (output)
= 0: successful exit
< 0: if INFO = -i, the i-th argument has an illegal value
6 Mar 2009 sorgql(3P)
