sorg2l

NAME

sorg2l - generate an m by n real matrix Q with orthonormal columns,

SYNOPSIS

  SUBROUTINE SORG2L( M, N, K, A, LDA, TAU, WORK, INFO)
  INTEGER M, N, K, LDA, INFO
  REAL A(LDA,*), TAU(*), WORK(*)
 
  SUBROUTINE SORG2L_64( M, N, K, A, LDA, TAU, WORK, INFO)
  INTEGER*8 M, N, K, LDA, INFO
  REAL A(LDA,*), TAU(*), WORK(*)

F95 INTERFACE

  SUBROUTINE ORG2L( [M], [N], [K], A, [LDA], TAU, [WORK], [INFO])
  INTEGER :: M, N, K, LDA, INFO
  REAL, DIMENSION(:) :: TAU, WORK
  REAL, DIMENSION(:,:) :: A
 
  SUBROUTINE ORG2L_64( [M], [N], [K], A, [LDA], TAU, [WORK], [INFO])
  INTEGER(8) :: M, N, K, LDA, INFO
  REAL, DIMENSION(:) :: TAU, WORK
  REAL, DIMENSION(:,:) :: A

C INTERFACE

#include <sunperf.h>

void sorg2l(int m, int n, int k, float *a, int lda, float *tau, int *info);

void sorg2l_64(long m, long n, long k, float *a, long lda, float *tau, long *info);

PURPOSE

sorg2l L generates an m by n real matrix Q with orthonormal columns, which is defined as the last n columns of a product of k elementary reflectors of order m

      Q  =  H(k) . . . H(2) H(1)

as returned by SGEQLF.

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 (n-k+i)-th column must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k, as returned by SGEQLF in the last k columns 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 SGEQLF.
* WORK (workspace): dimension(N)
* INFO (output)