zungl2(3P) Sun Performance Library zungl2(3P)NAMEzungl2 - generate an m-by-n complex matrix Q with orthonormal rows,
SYNOPSIS
SUBROUTINE ZUNGL2(M, N, K, A, LDA, TAU, WORK, INFO)
DOUBLE COMPLEX A(LDA,*), TAU(*), WORK(*)
INTEGER M, N, K, LDA, INFO
SUBROUTINE ZUNGL2_64(M, N, K, A, LDA, TAU, WORK, INFO)
DOUBLE COMPLEX A(LDA,*), TAU(*), WORK(*)
INTEGER*8 M, N, K, LDA, INFO
F95 INTERFACE
SUBROUTINE UNGL2([M], [N], [K], A, [LDA], TAU, [WORK], [INFO])
COMPLEX(8), DIMENSION(:) :: TAU, WORK
COMPLEX(8), DIMENSION(:,:) :: A
INTEGER :: M, N, K, LDA, INFO
SUBROUTINE UNGL2_64([M], [N], [K], A, [LDA], TAU, [WORK], [INFO])
COMPLEX(8), DIMENSION(:) :: TAU, WORK
COMPLEX(8), DIMENSION(:,:) :: A
INTEGER(8) :: M, N, K, LDA, INFO
C INTERFACE
#include <sunperf.h>
void zungl2(int m, int n, int k, doublecomplex *a, int lda, doublecom‐
plex *tau, int *info);
void zungl2_64(long m, long n, long k, doublecomplex *a, long lda, dou‐
blecomplex *tau, long *info);
PURPOSEzungl2 generates an m-by-n complex matrix Q with orthonormal rows,
which is defined as the first m rows of a product of k elementary
reflectors of order n
Q = H(k)' . . . H(2)' H(1)'
as returned by ZGELQF.
ARGUMENTS
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 i-th row must contain the vector which defines
the elementary reflector H(i), for i = 1,2,...,k, as returned
by ZGELQF in the first 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 elementary
reflector H(i), as returned by ZGELQF.
WORK (workspace)
dimension(M)
INFO (output)
= 0: successful exit
< 0: if INFO = -i, the i-th argument has an illegal value
6 Mar 2009 zungl2(3P)
