sorglq

NAME

sorglq - generate an M-by-N real matrix Q with orthonormal rows,

SYNOPSIS 

  SUBROUTINE SORGLQ( M, N, K, A, LDA, TAU, WORK, LDWORK, INFO)
  INTEGER M, N, K, LDA, LDWORK, INFO
  REAL A(LDA,*), TAU(*), WORK(*)
 
  SUBROUTINE SORGLQ_64( M, N, K, A, LDA, TAU, WORK, LDWORK, INFO)
  INTEGER*8 M, N, K, LDA, LDWORK, INFO
  REAL A(LDA,*), TAU(*), WORK(*)

F95 INTERFACE 

  SUBROUTINE ORGLQ( M, [N], [K], A, [LDA], TAU, [WORK], [LDWORK], 
 *       [INFO])
  INTEGER :: M, N, K, LDA, LDWORK, INFO
  REAL, DIMENSION(:) :: TAU, WORK
  REAL, DIMENSION(:,:) :: A
 
  SUBROUTINE ORGLQ_64( M, [N], [K], A, [LDA], TAU, [WORK], [LDWORK], 
 *       [INFO])
  INTEGER(8) :: M, N, K, LDA, LDWORK, INFO
  REAL, DIMENSION(:) :: TAU, WORK
  REAL, DIMENSION(:,:) :: A

C INTERFACE

#include <sunperf.h>

void sorglq(int m, int n, int k, float *a, int lda, float *tau, int *info);

void sorglq_64(long m, long n, long k, float *a, long lda, float *tau, long *info);

PURPOSE

sorglq generates an M-by-N real 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 SGELQF.

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 SGELQF 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 SGELQF.

* WORK (workspace)
On exit, if INFO = 0, WORK(1) returns the optimal LDWORK.

* LDWORK (input)
The dimension of the array WORK. LDWORK >= max(1,M). For optimum performance LDWORK >= M*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)