dlarfy.f man page

dlarfy.f

Synopsis

Functions/Subroutines

subroutine dlarfy (UPLO, N, V, INCV, TAU, C, LDC, WORK)
DLARFY

Function/Subroutine Documentation

subroutine dlarfy (character UPLO, integer N, double precision, dimension( * ) V, integer INCV, double precision TAU, double precision, dimension( ldc, * ) C, integer LDC, double precision, dimension( * ) WORK)

DLARFY

Purpose:

 DLARFY applies an elementary reflector, or Householder matrix, H,
 to an n x n symmetric matrix C, from both the left and the right.

 H is represented in the form

    H = I - tau * v * v'

 where  tau  is a scalar and  v  is a vector.

 If  tau  is  zero, then  H  is taken to be the unit matrix.
Parameters:

UPLO

          UPLO is CHARACTER*1
          Specifies whether the upper or lower triangular part of the
          symmetric matrix C is stored.
          = 'U':  Upper triangle
          = 'L':  Lower triangle

N

          N is INTEGER
          The number of rows and columns of the matrix C.  N >= 0.

V

          V is DOUBLE PRECISION array, dimension
                  (1 + (N-1)*abs(INCV))
          The vector v as described above.

INCV

          INCV is INTEGER
          The increment between successive elements of v.  INCV must
          not be zero.

TAU

          TAU is DOUBLE PRECISION
          The value tau as described above.

C

          C is DOUBLE PRECISION array, dimension (LDC, N)
          On entry, the matrix C.
          On exit, C is overwritten by H * C * H'.

LDC

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

WORK

          WORK is DOUBLE PRECISION array, dimension (N)
Author:

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Date:

December 2016

Definition at line 110 of file dlarfy.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

The man page dlarfy(3) is an alias of dlarfy.f(3).

Tue Nov 14 2017 Version 3.8.0 LAPACK