redhat man page for zunmrz

ZUNMRZ(l)								 )								 ZUNMRZ(l)

NAME
       ZUNMRZ - overwrite the general complex M-by-N matrix C with  SIDE = 'L' SIDE = 'R' TRANS = 'N'

SYNOPSIS
       SUBROUTINE ZUNMRZ( SIDE, TRANS, M, N, K, L, A, LDA, TAU, C, LDC, WORK, LWORK, INFO )

	   CHARACTER	  SIDE, TRANS

	   INTEGER	  INFO, K, L, LDA, LDC, LWORK, M, N

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

PURPOSE
       ZUNMRZ  overwrites  the	general  complex  M-by-N  matrix  C with SIDE = 'L' SIDE = 'R' TRANS = 'N': Q * C C * Q TRANS = 'C':	  Q**H * C
       C * Q**H

       where Q is a complex unitary matrix defined as the product of k elementary reflectors

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

       as returned by ZTZRZF. Q is of order M if SIDE = 'L' and of order N if SIDE = 'R'.

ARGUMENTS
       SIDE    (input) CHARACTER*1
	       = 'L': apply Q or Q**H from the Left;
	       = 'R': apply Q or Q**H from the Right.

       TRANS   (input) CHARACTER*1
	       = 'N':  No transpose, apply Q;
	       = 'C':  Conjugate transpose, apply Q**H.

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

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

       K       (input) INTEGER
	       The number of elementary reflectors whose product defines the matrix Q.	If SIDE = 'L', M >= K >= 0; if SIDE = 'R', N >= K >= 0.

       L       (input) INTEGER
	       The number of columns of the matrix A containing the meaningful part of the Householder reflectors.  If SIDE = 'L', M >= L >= 0, if
	       SIDE = 'R', N >= L >= 0.

       A       (input) COMPLEX*16 array, dimension
	       (LDA,M)	if SIDE = 'L', (LDA,N) if SIDE = 'R' The i-th row must contain the vector which defines the elementary reflector H(i), for
	       i = 1,2,...,k, as returned by ZTZRZF in the last k rows of its array argument A.  A is modified by  the	routine  but  restored	on
	       exit.

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

       TAU     (input) COMPLEX*16 array, dimension (K)
	       TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by ZTZRZF.

       C       (input/output) COMPLEX*16 array, dimension (LDC,N)
	       On entry, the M-by-N matrix C.  On exit, C is overwritten by Q*C or Q**H*C or C*Q**H or C*Q.

       LDC     (input) INTEGER
	       The leading dimension of the array C. LDC >= max(1,M).

       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.  If SIDE = 'L', LWORK >= max(1,N); if SIDE = 'R', LWORK >= max(1,M).  For optimum performance
	       LWORK >= N*NB if SIDE = 'L', and LWORK >= M*NB if SIDE = 'R', 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
       Based on contributions by
	 A. Petitet, Computer Science Dept., Univ. of Tenn., Knoxville, USA

LAPACK version 3.0						   15 June 2000 							 ZUNMRZ(l)