zungqr(l) [redhat man page]

ZUNGQR(l)								 )								 ZUNGQR(l)

NAME

       ZUNGQR - generate an M-by-N complex matrix Q with orthonormal columns,

SYNOPSIS

       SUBROUTINE ZUNGQR( M, N, K, A, LDA, TAU, WORK, LWORK, INFO )

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

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

PURPOSE

       ZUNGQR  generates an M-by-N complex matrix Q with orthonormal columns, which is defined as the first N columns of a product of K elementary
       reflectors of order M

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

       as returned by ZGEQRF.

ARGUMENTS

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

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

       K       (input) INTEGER
	       The number of elementary reflectors whose product defines the matrix Q. N >= K >= 0.

       A       (input/output) COMPLEX*16 array, dimension (LDA,N)
	       On entry, the i-th column must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k,  as  returned	by
	       ZGEQRF in the first k columns of its array argument A.  On exit, the M-by-N matrix Q.

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

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

       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,N).  For optimum performance LWORK >= N*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 has an illegal value

LAPACK version 3.0						   15 June 2000 							 ZUNGQR(l)

ZUNGQL(l)								 )								 ZUNGQL(l)

NAME

       ZUNGQL - generate an M-by-N complex matrix Q with orthonormal columns,

SYNOPSIS

       SUBROUTINE ZUNGQL( M, N, K, A, LDA, TAU, WORK, LWORK, INFO )

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

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

PURPOSE

       ZUNGQL  generates  an M-by-N complex 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 ZGEQLF.

ARGUMENTS

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

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

       K       (input) INTEGER
	       The number of elementary reflectors whose product defines the matrix Q. N >= K >= 0.

       A       (input/output) COMPLEX*16 array, dimension (LDA,N)
	       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 ZGEQLF in the last k columns of its array argument A.  On exit, the M-by-N matrix Q.

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

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

       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,N).  For optimum performance LWORK >= N*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 has an illegal value

LAPACK version 3.0						   15 June 2000 							 ZUNGQL(l)