👤
Home Man
Search
Today's Posts
Register

Linux & Unix Commands - Search Man Pages
Man Page or Keyword Search:
Select Section of Man Page:
Select Man Page Repository:

RedHat 9 (Linux i386) - man page for zgerqf (redhat section l)

ZGERQF(l)					)					ZGERQF(l)

NAME
       ZGERQF - compute an RQ factorization of a complex M-by-N matrix A

SYNOPSIS
       SUBROUTINE ZGERQF( M, N, A, LDA, TAU, WORK, LWORK, INFO )

	   INTEGER	  INFO, LDA, LWORK, M, N

	   COMPLEX*16	  A( LDA, * ), TAU( * ), WORK( * )

PURPOSE
       ZGERQF computes an RQ factorization of a complex M-by-N matrix A: A = R * Q.

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) COMPLEX*16 array, dimension (LDA,N)
	       On entry, the M-by-N matrix A.  On exit, if m <= n, the upper triangle of the sub-
	       array A(1:m,n-m+1:n) contains the M-by-M upper triangular matrix R; if m >= n, the
	       elements  on  and  above  the (m-n)-th subdiagonal contain the M-by-N upper trape-
	       zoidal matrix R; the remaining elements, with the array TAU, represent the unitary
	       matrix  Q  as  a  product of min(m,n) elementary reflectors (see Further Details).
	       LDA     (input) INTEGER The leading dimension of the array A.  LDA >= max(1,M).

       TAU     (output) COMPLEX*16 array, dimension (min(M,N))
	       The scalar factors of the elementary reflectors (see Further Details).

       WORK    (workspace/output) COMPLEX*16 array, dimension (LWORK)
	       On exit, if INFO = 0, WORK(1) returns the optimal LWORK.

       LWORK   (input) INTEGER
	       The dimension of the array WORK.  LWORK	>=  max(1,M).	For  optimum  performance
	       LWORK >= M*NB, where NB is the optimal blocksize.

	       If  LWORK = -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 LWORK is issued by XERBLA.

       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(k)', where k = min(m,n).

       Each H(i) has the form

	  H(i) = I - tau * v * v'

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

LAPACK version 3.0			   15 June 2000 				ZGERQF(l)


All times are GMT -4. The time now is 02:01 PM.

Unix & Linux Forums Content Copyrightę1993-2018. All Rights Reserved.
×
UNIX.COM Login
Username:
Password:  
Show Password