chpmv.f man page

chpmv.f —

Synopsis

Functions/Subroutines

subroutine chpmv (UPLO, N, ALPHA, AP, X, INCX, BETA, Y, INCY)
CHPMV

Function/Subroutine Documentation

subroutine chpmv (characterUPLO, integerN, complexALPHA, complex, dimension(*)AP, complex, dimension(*)X, integerINCX, complexBETA, complex, dimension(*)Y, integerINCY)

CHPMV Purpose:

CHPMV  performs the matrix-vector operation

   y := alpha*A*x + beta*y,

where alpha and beta are scalars, x and y are n element vectors and
A is an n by n hermitian matrix, supplied in packed form.

Parameters:

UPLO

UPLO is CHARACTER*1
 On entry, UPLO specifies whether the upper or lower
 triangular part of the matrix A is supplied in the packed
 array AP as follows:

    UPLO = 'U' or 'u'   The upper triangular part of A is
                        supplied in AP.

    UPLO = 'L' or 'l'   The lower triangular part of A is
                        supplied in AP.

N

N is INTEGER
 On entry, N specifies the order of the matrix A.
 N must be at least zero.

ALPHA

ALPHA is COMPLEX
 On entry, ALPHA specifies the scalar alpha.

AP

AP is COMPLEX array of DIMENSION at least
 ( ( n*( n + 1 ) )/2 ).
 Before entry with UPLO = 'U' or 'u', the array AP must
 contain the upper triangular part of the hermitian matrix
 packed sequentially, column by column, so that AP( 1 )
 contains a( 1, 1 ), AP( 2 ) and AP( 3 ) contain a( 1, 2 )
 and a( 2, 2 ) respectively, and so on.
 Before entry with UPLO = 'L' or 'l', the array AP must
 contain the lower triangular part of the hermitian matrix
 packed sequentially, column by column, so that AP( 1 )
 contains a( 1, 1 ), AP( 2 ) and AP( 3 ) contain a( 2, 1 )
 and a( 3, 1 ) respectively, and so on.
 Note that the imaginary parts of the diagonal elements need
 not be set and are assumed to be zero.

X

X is COMPLEX array of dimension at least
 ( 1 + ( n - 1 )*abs( INCX ) ).
 Before entry, the incremented array X must contain the n
 element vector x.

INCX

INCX is INTEGER
 On entry, INCX specifies the increment for the elements of
 X. INCX must not be zero.

BETA

BETA is COMPLEX
 On entry, BETA specifies the scalar beta. When BETA is
 supplied as zero then Y need not be set on input.

Y

Y is COMPLEX array of dimension at least
 ( 1 + ( n - 1 )*abs( INCY ) ).
 Before entry, the incremented array Y must contain the n
 element vector y. On exit, Y is overwritten by the updated
 vector y.

INCY

INCY is INTEGER
 On entry, INCY specifies the increment for the elements of
 Y. INCY must not be zero.

Author:

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Date:

November 2011

Further Details:

Level 2 Blas routine.
The vector and matrix arguments are not referenced when N = 0, or M = 0

-- Written on 22-October-1986.
   Jack Dongarra, Argonne National Lab.
   Jeremy Du Croz, Nag Central Office.
   Sven Hammarling, Nag Central Office.
   Richard Hanson, Sandia National Labs.

Definition at line 150 of file chpmv.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

chpmv(3) is an alias of chpmv.f(3).

Sat Nov 16 2013 Version 3.4.2 LAPACK