Contents
dorgr2 - generate an m by n real matrix Q with orthonormal
rows,
SUBROUTINE DORGR2(M, N, K, A, LDA, TAU, WORK, INFO)
INTEGER M, N, K, LDA, INFO
DOUBLE PRECISION A(LDA,*), TAU(*), WORK(*)
SUBROUTINE DORGR2_64(M, N, K, A, LDA, TAU, WORK, INFO)
INTEGER*8 M, N, K, LDA, INFO
DOUBLE PRECISION A(LDA,*), TAU(*), WORK(*)
F95 INTERFACE
SUBROUTINE ORGR2([M], [N], [K], A, [LDA], TAU, [WORK], [INFO])
INTEGER :: M, N, K, LDA, INFO
REAL(8), DIMENSION(:) :: TAU, WORK
REAL(8), DIMENSION(:,:) :: A
SUBROUTINE ORGR2_64([M], [N], [K], A, [LDA], TAU, [WORK], [INFO])
INTEGER(8) :: M, N, K, LDA, INFO
REAL(8), DIMENSION(:) :: TAU, WORK
REAL(8), DIMENSION(:,:) :: A
C INTERFACE
#include <sunperf.h>
void dorgr2(int m, int n, int k, double *a, int lda, double
*tau, int *info);
void dorgr2_64(long m, long n, long k, double *a, long lda,
double *tau, long *info);
dorgr2 generates an m by n real matrix Q with orthonormal
rows, which is defined as the last m rows of a product of k
elementary reflectors of order n
Q = H(1) H(2) . . . H(k)
as returned by SGERQF.
M (input) The number of rows of the matrix Q. M >= 0.
N (input) The number of columns of the matrix Q. N >= M.
K (input) The number of elementary reflectors whose product
defines the matrix Q. M >= K >= 0.
A (input/output)
On entry, the (m-k+i)-th row must contain the vec-
tor which defines the elementary reflector H(i),
for i = 1,2,...,k, as returned by SGERQF in the
last k rows 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 SGERQF.
WORK (workspace)
dimension(M)
INFO (output)
= 0: successful exit
< 0: if INFO = -i, the i-th argument has an ille-
gal value