LAPACK  3.4.2 LAPACK: Linear Algebra PACKage
clarzb.f File Reference

Go to the source code of this file.

## Functions/Subroutines

subroutine clarzb (SIDE, TRANS, DIRECT, STOREV, M, N, K, L, V, LDV, T, LDT, C, LDC, WORK, LDWORK)
CLARZB applies a block reflector or its conjugate-transpose to a general matrix.

## Function/Subroutine Documentation

 subroutine clarzb ( character SIDE, character TRANS, character DIRECT, character STOREV, integer M, integer N, integer K, integer L, complex, dimension( ldv, * ) V, integer LDV, complex, dimension( ldt, * ) T, integer LDT, complex, dimension( ldc, * ) C, integer LDC, complex, dimension( ldwork, * ) WORK, integer LDWORK )

CLARZB applies a block reflector or its conjugate-transpose to a general matrix.

Purpose:
``` CLARZB applies a complex block reflector H or its transpose H**H
to a complex distributed M-by-N  C from the left or the right.

Currently, only STOREV = 'R' and DIRECT = 'B' are supported.```
Parameters:
 [in] SIDE ``` SIDE is CHARACTER*1 = 'L': apply H or H**H from the Left = 'R': apply H or H**H from the Right``` [in] TRANS ``` TRANS is CHARACTER*1 = 'N': apply H (No transpose) = 'C': apply H**H (Conjugate transpose)``` [in] DIRECT ``` DIRECT is CHARACTER*1 Indicates how H is formed from a product of elementary reflectors = 'F': H = H(1) H(2) . . . H(k) (Forward, not supported yet) = 'B': H = H(k) . . . H(2) H(1) (Backward)``` [in] STOREV ``` STOREV is CHARACTER*1 Indicates how the vectors which define the elementary reflectors are stored: = 'C': Columnwise (not supported yet) = 'R': Rowwise``` [in] M ``` M is INTEGER The number of rows of the matrix C.``` [in] N ``` N is INTEGER The number of columns of the matrix C.``` [in] K ``` K is INTEGER The order of the matrix T (= the number of elementary reflectors whose product defines the block reflector).``` [in] L ``` L is INTEGER The number of columns of the matrix V containing the meaningful part of the Householder reflectors. If SIDE = 'L', M >= L >= 0, if SIDE = 'R', N >= L >= 0.``` [in] V ``` V is COMPLEX array, dimension (LDV,NV). If STOREV = 'C', NV = K; if STOREV = 'R', NV = L.``` [in] LDV ``` LDV is INTEGER The leading dimension of the array V. If STOREV = 'C', LDV >= L; if STOREV = 'R', LDV >= K.``` [in] T ``` T is COMPLEX array, dimension (LDT,K) The triangular K-by-K matrix T in the representation of the block reflector.``` [in] LDT ``` LDT is INTEGER The leading dimension of the array T. LDT >= K.``` [in,out] C ``` C is COMPLEX array, dimension (LDC,N) On entry, the M-by-N matrix C. On exit, C is overwritten by H*C or H**H*C or C*H or C*H**H.``` [in] LDC ``` LDC is INTEGER The leading dimension of the array C. LDC >= max(1,M).``` [out] WORK ` WORK is COMPLEX array, dimension (LDWORK,K)` [in] LDWORK ``` LDWORK is INTEGER The leading dimension of the array WORK. If SIDE = 'L', LDWORK >= max(1,N); if SIDE = 'R', LDWORK >= max(1,M).```
Date:
September 2012
Contributors:
A. Petitet, Computer Science Dept., Univ. of Tenn., Knoxville, USA
Further Details:
` `

Definition at line 183 of file clarzb.f.

Here is the call graph for this function:

Here is the caller graph for this function: