clarz.f man page

clarz.f —

Synopsis

Functions/Subroutines

subroutine clarz (SIDE, M, N, L, V, INCV, TAU, C, LDC, WORK)
CLARZ applies an elementary reflector (as returned by stzrzf) to a general matrix.

Function/Subroutine Documentation

subroutine clarz (characterSIDE, integerM, integerN, integerL, complex, dimension( * )V, integerINCV, complexTAU, complex, dimension( ldc, * )C, integerLDC, complex, dimension( * )WORK)

CLARZ applies an elementary reflector (as returned by stzrzf) to a general matrix.

Purpose:

CLARZ applies a complex elementary reflector H to a complex
M-by-N matrix C, from either the left or the right. H is represented
in the form

      H = I - tau * v * v**H

where tau is a complex scalar and v is a complex vector.

If tau = 0, then H is taken to be the unit matrix.

To apply H**H (the conjugate transpose of H), supply conjg(tau) instead
tau.

H is a product of k elementary reflectors as returned by CTZRZF.

Parameters:

SIDE

SIDE is CHARACTER*1
= 'L': form  H * C
= 'R': form  C * H

M

M is INTEGER
The number of rows of the matrix C.

N

N is INTEGER
The number of columns of the matrix C.

L

L is INTEGER
The number of entries of the vector V containing
the meaningful part of the Householder vectors.
If SIDE = 'L', M >= L >= 0, if SIDE = 'R', N >= L >= 0.

V

V is COMPLEX array, dimension (1+(L-1)*abs(INCV))
The vector v in the representation of H as returned by
CTZRZF. V is not used if TAU = 0.

INCV

INCV is INTEGER
The increment between elements of v. INCV <> 0.

TAU

TAU is COMPLEX
The value tau in the representation of H.

C

C is COMPLEX array, dimension (LDC,N)
On entry, the M-by-N matrix C.
On exit, C is overwritten by the matrix H * C if SIDE = 'L',
or C * H if SIDE = 'R'.

LDC

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

WORK

WORK is COMPLEX array, dimension
               (N) if SIDE = 'L'
            or (M) if SIDE = 'R'

Author:

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Date:

September 2012

Contributors:

A. Petitet, Computer Science Dept., Univ. of Tenn., Knoxville, USA

Further Details:

Definition at line 148 of file clarz.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

clarz(3) is an alias of clarz.f(3).

Sat Nov 16 2013 Version 3.4.2 LAPACK