# 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

Univ. of Colorado Denver

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