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sgeqpf(3) [centos man page]

sgeqpf.f(3)							      LAPACK							       sgeqpf.f(3)

NAME

       sgeqpf.f -

SYNOPSIS

   Functions/Subroutines
       subroutine sgeqpf (M, N, A, LDA, JPVT, TAU, WORK, INFO)
	   SGEQPF

Function/Subroutine Documentation
   subroutine sgeqpf (integerM, integerN, real, dimension( lda, * )A, integerLDA, integer, dimension( * )JPVT, real, dimension( * )TAU, real,
       dimension( * )WORK, integerINFO)
       SGEQPF

       Purpose:

	    This routine is deprecated and has been replaced by routine SGEQP3.

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

       Parameters:
	   M

		     M is INTEGER
		     The number of rows of the matrix A. M >= 0.

	   N

		     N is INTEGER
		     The number of columns of the matrix A. N >= 0

	   A

		     A is REAL array, dimension (LDA,N)
		     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

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

	   JPVT

		     JPVT is INTEGER array, dimension (N)
		     On entry, if JPVT(i) .ne. 0, the i-th column of A is permuted
		     to the front of A*P (a leading column); if JPVT(i) = 0,
		     the i-th column of A is a free column.
		     On exit, if JPVT(i) = k, then the i-th column of A*P
		     was the k-th column of A.

	   TAU

		     TAU is REAL array, dimension (min(M,N))
		     The scalar factors of the elementary reflectors.

	   WORK

		     WORK is REAL array, dimension (3*N)

	   INFO

		     INFO is INTEGER
		     = 0:  successful exit
		     < 0:  if INFO = -i, the i-th argument had an illegal value

       Author:
	   Univ. of Tennessee

	   Univ. of California Berkeley

	   Univ. of Colorado Denver

	   NAG Ltd.

       Date:
	   November 2011

       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**T

	     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.

	     Partial column norm updating strategy modified by
	       Z. Drmac and Z. Bujanovic, Dept. of Mathematics,
	       University of Zagreb, Croatia.
	     -- April 2011							--
	     For more details see LAPACK Working Note 176.

       Definition at line 143 of file sgeqpf.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

Version 3.4.2							  Tue Sep 25 2012						       sgeqpf.f(3)

Check Out this Related Man Page

SGEQPF(l)								 )								 SGEQPF(l)

NAME

       SGEQPF - routine is deprecated and has been replaced by routine SGEQP3

SYNOPSIS

       SUBROUTINE SGEQPF( M, N, A, LDA, JPVT, TAU, WORK, INFO )

	   INTEGER	  INFO, LDA, M, N

	   INTEGER	  JPVT( * )

	   REAL 	  A( LDA, * ), TAU( * ), WORK( * )

PURPOSE

       This  routine  is deprecated and has been replaced by routine SGEQP3.  SGEQPF computes a QR factorization with column pivoting of a real M-
       by-N matrix A: A*P = Q*R.

ARGUMENTS

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

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

       A       (input/output) REAL array, dimension (LDA,N)
	       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) INTEGER
	       The leading dimension of the array A. LDA >= max(1,M).

       JPVT    (input/output) INTEGER array, dimension (N)
	       On entry, if JPVT(i) .ne. 0, the i-th column of A is permuted to the front of A*P (a leading column); if JPVT(i) = 0, the i-th col-
	       umn of A is a free column.  On exit, if JPVT(i) = k, then the i-th column of A*P was the k-th column of A.

       TAU     (output) REAL array, dimension (min(M,N))
	       The scalar factors of the elementary reflectors.

       WORK    (workspace) REAL array, dimension (3*N)

       INFO    (output) INTEGER
	       = 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.

LAPACK test version 3.0 					   15 June 2000 							 SGEQPF(l)
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