cungrq - generate an M-by-N complex matrix Q with orthonormal rows,
SUBROUTINE CUNGRQ( M, N, K, A, LDA, TAU, WORK, LWORK, INFO) COMPLEX A(LDA,*), TAU(*), WORK(*) INTEGER M, N, K, LDA, LWORK, INFO
SUBROUTINE CUNGRQ_64( M, N, K, A, LDA, TAU, WORK, LWORK, INFO) COMPLEX A(LDA,*), TAU(*), WORK(*) INTEGER*8 M, N, K, LDA, LWORK, INFO
SUBROUTINE UNGRQ( M, [N], [K], A, [LDA], TAU, [WORK], [LWORK], [INFO]) COMPLEX, DIMENSION(:) :: TAU, WORK COMPLEX, DIMENSION(:,:) :: A INTEGER :: M, N, K, LDA, LWORK, INFO
SUBROUTINE UNGRQ_64( M, [N], [K], A, [LDA], TAU, [WORK], [LWORK], * [INFO]) COMPLEX, DIMENSION(:) :: TAU, WORK COMPLEX, DIMENSION(:,:) :: A INTEGER(8) :: M, N, K, LDA, LWORK, INFO
#include <sunperf.h>
void cungrq(int m, int n, int k, complex *a, int lda, complex *tau, int *info);
void cungrq_64(long m, long n, long k, complex *a, long lda, complex *tau, long *info);
cungrq generates an M-by-N complex 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 CGERQF.
TAU(i)
must contain the scalar factor of the elementary
reflector H(i), as returned by CGERQF.
WORK(1)
returns the optimal LWORK.
If LWORK = -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 LWORK is issued by XERBLA.
= 0: successful exit
< 0: if INFO = -i, the i-th argument has an illegal value