dgeqpf (3p)

Name

dgeqpf - routine is deprecated and has been replaced by routine DGEQP3

Synopsis

SUBROUTINE DGEQPF(M, N, A, LDA, JPIVOT, TAU, WORK, INFO)

INTEGER M, N, LDA, INFO
INTEGER JPIVOT(*)
DOUBLE PRECISION A(LDA,*), TAU(*), WORK(*)

SUBROUTINE DGEQPF_64(M, N, A, LDA, JPIVOT, TAU, WORK, INFO)

INTEGER*8 M, N, LDA, INFO
INTEGER*8 JPIVOT(*)
DOUBLE PRECISION A(LDA,*), TAU(*), WORK(*)




F95 INTERFACE
SUBROUTINE GEQPF(M, N, A, LDA, JPIVOT, TAU, WORK, INFO)

INTEGER :: M, N, LDA, INFO
INTEGER, DIMENSION(:) :: JPIVOT
REAL(8), DIMENSION(:) :: TAU, WORK
REAL(8), DIMENSION(:,:) :: A

SUBROUTINE GEQPF_64(M, N, A, LDA, JPIVOT, TAU, WORK, INFO)

INTEGER(8) :: M, N, LDA, INFO
INTEGER(8), DIMENSION(:) :: JPIVOT
REAL(8), DIMENSION(:) :: TAU, WORK
REAL(8), DIMENSION(:,:) :: A




C INTERFACE
#include <sunperf.h>

void dgeqpf(int m, int n, double *a, int lda, int *jpivot, double *tau,
int *info);

void dgeqpf_64(long m, long n, double *a, long lda, long *jpivot,  dou-
ble *tau, long *info);

Description

Oracle Solaris Studio Performance Library                           dgeqpf(3P)



NAME
       dgeqpf - routine is deprecated and has been replaced by routine DGEQP3


SYNOPSIS
       SUBROUTINE DGEQPF(M, N, A, LDA, JPIVOT, TAU, WORK, INFO)

       INTEGER M, N, LDA, INFO
       INTEGER JPIVOT(*)
       DOUBLE PRECISION A(LDA,*), TAU(*), WORK(*)

       SUBROUTINE DGEQPF_64(M, N, A, LDA, JPIVOT, TAU, WORK, INFO)

       INTEGER*8 M, N, LDA, INFO
       INTEGER*8 JPIVOT(*)
       DOUBLE PRECISION A(LDA,*), TAU(*), WORK(*)




   F95 INTERFACE
       SUBROUTINE GEQPF(M, N, A, LDA, JPIVOT, TAU, WORK, INFO)

       INTEGER :: M, N, LDA, INFO
       INTEGER, DIMENSION(:) :: JPIVOT
       REAL(8), DIMENSION(:) :: TAU, WORK
       REAL(8), DIMENSION(:,:) :: A

       SUBROUTINE GEQPF_64(M, N, A, LDA, JPIVOT, TAU, WORK, INFO)

       INTEGER(8) :: M, N, LDA, INFO
       INTEGER(8), DIMENSION(:) :: JPIVOT
       REAL(8), DIMENSION(:) :: TAU, WORK
       REAL(8), DIMENSION(:,:) :: A




   C INTERFACE
       #include <sunperf.h>

       void dgeqpf(int m, int n, double *a, int lda, int *jpivot, double *tau,
                 int *info);

       void dgeqpf_64(long m, long n, double *a, long lda, long *jpivot,  dou-
                 ble *tau, long *info);



PURPOSE
       dgeqpf routine is deprecated and has been replaced by routine DGEQP3.

       DGEQPF computes a QR factorization with column pivoting of a real M-by-
       N matrix A: A*P = Q*R.


ARGUMENTS
       M (input) The number of rows of the matrix A. M >= 0.


       N (input) The number of columns of the matrix A. N >= 0


       A (input/output)
                 On entry, the M-by-N matrix A.  On exit, the  upper  triangle
                 of  the  array  contains  the  min(M,N)-by-N upper triangular
                 matrix R; the elements below the diagonal, together with  the
                 array  TAU, represent the orthogonal matrix Q as a product of
                 min(m,n) elementary reflectors.


       LDA (input)
                 The leading dimension of the array A. LDA >= max(1,M).


       JPIVOT (input/output)
                 On entry, if JPIVOT(i) .ne. 0, the i-th column of A  is  per-
                 muted  to the front of A*P (a leading column); if JPIVOT(i) =
                 0, the i-th column of A  is  a  free  column.   On  exit,  if
                 JPIVOT(i)  = k, then the i-th column of A*P was the k-th col-
                 umn of A.


       TAU (output)
                 The scalar factors of the elementary reflectors.


       WORK (workspace)
                 dimension(3*N)

       INFO (output)
                 = 0:  successful exit
                 < 0:  if INFO = -i, the i-th argument had an illegal value

FURTHER DETAILS
       The matrix Q is represented as a product of elementary reflectors

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

       Each H(i) has the form

          H = I - tau * v * v'

       where tau is a real scalar, and v is a real vector with
       v(1:i-1) = 0 and v(i) = 1; v(i+1:m) is stored on exit in A(i+1:m,i).

       The matrix P is represented in jpvt as follows: If
          jpvt(j) = i
       then the jth column of P is the ith canonical unit vector.




                                  7 Nov 2015                        dgeqpf(3P)