dlarfy.f

Section: LAPACK (3)
Updated: Tue Nov 14 2017
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NAME

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.


 

Index

NAME
SYNOPSIS
Functions/Subroutines
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)
Author
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