Contents
dorgql - generate an M-by-N real matrix Q with orthonormal
columns,
SUBROUTINE DORGQL(M, N, K, A, LDA, TAU, WORK, LDWORK, INFO)
INTEGER M, N, K, LDA, LDWORK, INFO
DOUBLE PRECISION A(LDA,*), TAU(*), WORK(*)
SUBROUTINE DORGQL_64(M, N, K, A, LDA, TAU, WORK, LDWORK, INFO)
INTEGER*8 M, N, K, LDA, LDWORK, INFO
DOUBLE PRECISION 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(8), DIMENSION(:) :: TAU, WORK
REAL(8), DIMENSION(:,:) :: A
SUBROUTINE ORGQL_64(M, [N], [K], A, [LDA], TAU, [WORK], [LDWORK],
[INFO])
INTEGER(8) :: M, N, K, LDA, LDWORK, INFO
REAL(8), DIMENSION(:) :: TAU, WORK
REAL(8), DIMENSION(:,:) :: A
C INTERFACE
#include <sunperf.h>
void dorgql(int m, int n, int k, double *a, int lda, double
*tau, int *info);
void dorgql_64(long m, long n, long k, double *a, long lda,
double *tau, long *info);
dorgql 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.
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 argument 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 ele-
mentary 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 routine 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 ille-
gal value