dorg2r(3P) Sun Performance Library dorg2r(3P)NAMEdorg2r - generate an m by n real matrix Q with orthonormal columns,
SYNOPSIS
SUBROUTINE DORG2R(M, N, K, A, LDA, TAU, WORK, INFO)
INTEGER M, N, K, LDA, INFO
DOUBLE PRECISION A(LDA,*), TAU(*), WORK(*)
SUBROUTINE DORG2R_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 ORG2R([M], [N], [K], A, [LDA], TAU, [WORK], [INFO])
INTEGER :: M, N, K, LDA, INFO
REAL(8), DIMENSION(:) :: TAU, WORK
REAL(8), DIMENSION(:,:) :: A
SUBROUTINE ORG2R_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 dorg2r(int m, int n, int k, double *a, int lda, double *tau, int
*info);
void dorg2r_64(long m, long n, long k, double *a, long lda, double
*tau, long *info);
PURPOSEdorg2r R generates an m by n real matrix Q with orthonormal columns,
which is defined as the first n columns of a product of k elementary
reflectors of order m
Q = H(1)H(2) . . . H(k)
as returned by DGEQRF.
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 i-th column must contain the vector which
defines the elementary reflector H(i), for i = 1,2,...,k, as
returned by DGEQRF in the first 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 DGEQRF.
WORK (workspace)
dimension(N)
INFO (output)
= 0: successful exit
< 0: if INFO = -i, the i-th argument has an illegal value
6 Mar 2009 dorg2r(3P)
