CXML

LAPACK version 3.0

zlarfb(3)

PURPOSE

ZLARFB - applie a complex block reflector H or its transpose H' to a complex M-by-N matrix C, from either the left or the right

SYNTAX

SUBROUTINE ZLARFB( SIDE, TRANS, DIRECT, STOREV, M, N, K, V, LDV, T, LDT, C, LDC, WORK, LDWORK ) CHARACTER DIRECT, SIDE, STOREV, TRANS INTEGER K, LDC, LDT, LDV, LDWORK, M, N COMPLEX*16 C( LDC, * ), T( LDT, * ), V( LDV, * ), WORK( LDWORK, * )

DESCRIPTION

ZLARFB applies a complex block reflector H or its transpose H' to a complex M-by-N matrix C, from either the left or the right.

ARGUMENTS

SIDE (input) CHARACTER*1 = 'L': apply H or H' from the Left = 'R': apply H or H' from the Right TRANS (input) CHARACTER*1 = 'N': apply H (No transpose) = 'C': apply H' (Conjugate transpose) DIRECT (input) CHARACTER*1 Indicates how H is formed from a product of elementary reflectors = 'F': H = H(1) H(2) . . . H(k) (Forward) = 'B': H = H(k) . . . H(2) H(1) (Backward) STOREV (input) CHARACTER*1 Indicates how the vectors which define the elementary reflectors are stored: = 'C': Columnwise = 'R': Rowwise M (input) INTEGER The number of rows of the matrix C. N (input) INTEGER The number of columns of the matrix C. K (input) INTEGER The order of the matrix T (= the number of elementary reflectors whose product defines the block reflector). V (input) COMPLEX*16 array, dimension (LDV,K) if STOREV = 'C' (LDV,M) if STOREV = 'R' and SIDE = 'L' (LDV,N) if STOREV = 'R' and SIDE = 'R' The matrix V. See further details. LDV (input) INTEGER The leading dimension of the array V. If STOREV = 'C' and SIDE = 'L', LDV >= max(1,M); if STOREV = 'C' and SIDE = 'R', LDV >= max(1,N); if STOREV = 'R', LDV >= K. T (input) COMPLEX*16 array, dimension (LDT,K) The triangular K-by-K matrix T in the representation of the block reflector. LDT (input) INTEGER The leading dimension of the array T. LDT >= K. C (input/output) COMPLEX*16 array, dimension (LDC,N) On entry, the M-by-N matrix C. On exit, C is overwritten by H*C or H'*C or C*H or C*H'. LDC (input) INTEGER The leading dimension of the array C. LDC >= max(1,M). WORK (workspace) COMPLEX*16 array, dimension (LDWORK,K) LDWORK (input) INTEGER The leading dimension of the array WORK. If SIDE = 'L', LDWORK >= max(1,N); if SIDE = 'R', LDWORK >= max(1,M).

CXML Home Page

Index of CXML Routines