slarf.f man page

slarf.f —

Synopsis

Functions/Subroutines

subroutine slarf (SIDE, M, N, V, INCV, TAU, C, LDC, WORK)
SLARF applies an elementary reflector to a general rectangular matrix.

Function/Subroutine Documentation

subroutine slarf (characterSIDE, integerM, integerN, real, dimension( * )V, integerINCV, realTAU, real, dimension( ldc, * )C, integerLDC, real, dimension( * )WORK)

SLARF applies an elementary reflector to a general rectangular matrix.

Purpose:

SLARF applies a real elementary reflector H to a real m by n matrix
C, from either the left or the right. H is represented in the form

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

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

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

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.

V

V is REAL array, dimension
           (1 + (M-1)*abs(INCV)) if SIDE = 'L'
        or (1 + (N-1)*abs(INCV)) if SIDE = 'R'
The vector v in the representation of H. V is not used if
TAU = 0.

INCV

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

TAU

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

C

C is REAL 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 REAL 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

Definition at line 125 of file slarf.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

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

Sat Nov 16 2013 Version 3.4.2 LAPACK