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single_eig(3) LAPACK single_eig(3)

NAME

single_eig

SYNOPSIS

Functions


subroutine slarfy (UPLO, N, V, INCV, TAU, C, LDC, WORK)
SLARFY

Detailed Description

This is the group of real LAPACK TESTING EIG routines.

Function Documentation

subroutine slarfy (character UPLO, integer N, real, dimension( * ) V, integer INCV, real TAU, real, dimension( ldc, * ) C, integer LDC, real, dimension( * ) WORK)

SLARFY

Purpose:

 SLARFY 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 REAL 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 REAL
          The value tau as described above.

C

          C is REAL 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 REAL array, dimension (N)

Author:

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Date:

December 2016

Author

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