# clarfy.f - Man Page

TESTING/EIG/clarfy.f

## Synopsis

### Functions/Subroutines

subroutine clarfy (uplo, n, v, incv, tau, c, ldc, work)
CLARFY

## Function/Subroutine Documentation

### subroutine clarfy (character uplo, integer n, complex, dimension( * ) v, integer incv, complex tau, complex, dimension( ldc, * ) c, integer ldc, complex, dimension( * ) work)

CLARFY

Purpose:

``` CLARFY applies an elementary reflector, or Householder matrix, H,
to an n x n Hermitian 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
Hermitian 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 COMPLEX 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 COMPLEX
The value tau as described above.```

C

```          C is COMPLEX 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 COMPLEX array, dimension (N)`
Author

Univ. of Tennessee

Univ. of California Berkeley

NAG Ltd.

Definition at line 107 of file clarfy.f.

## Author

Generated automatically by Doxygen for LAPACK from the source code.

## Referenced By

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

Tue Nov 28 2023 12:08:41 Version 3.12.0 LAPACK