CHPMV (3) Linux Manual 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
N
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 is INTEGER
ALPHA
On entry, N specifies the order of the matrix A.
N must be at least zero.ALPHA is COMPLEX
AP
On entry, ALPHA specifies the scalar alpha.AP is COMPLEX array of DIMENSION at least
X
( ( 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 is COMPLEX array of dimension at least
INCX
( 1 + ( n – 1 )*abs( INCX ) ).
Before entry, the incremented array X must contain the n
element vector x.INCX is INTEGER
BETA
On entry, INCX specifies the increment for the elements of
X. INCX must not be zero.BETA is COMPLEX
Y
On entry, BETA specifies the scalar beta. When BETA is
supplied as zero then Y need not be set on input.Y is COMPLEX array of dimension at least
INCY
( 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 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.