C Library Functions - zhpmv (3)
NAME
zhpmv(3f) - [BLAS:COMPLEX_16_BLAS_LEVEL2]
CONTENTS
Synopsis
Definition
Options
Y
Authors
Further Details
See Also
SYNOPSIS
subroutine zhpmv(uplo,n,alpha,ap,x,incx,beta,y,incy)
.. Scalar Arguments .. complex(kind=real64),intent(in) :: alpha,beta integer,intent(in) :: incx,incy,n character,intent(in) :: uplo .. .. Array Arguments .. complex(kind=real64),intent(in) :: ap(*),x(*) complex(kind=real64),intent(inout) :: y(*) ..
DEFINITION
ZHPMV 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.
OPTIONS
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(kind=real64) On entry, ALPHA specifies the scalar alpha.
AP
AP is complex(kind=real64) array, 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(kind=real64) array, 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(kind=real64) 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(kind=real64) array, 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.
AUTHORS
o Univ. of Tennessee o Univ. of California Berkeley o Univ. of Colorado Denver o NAG Ltd. date:December 2016
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.
SEE ALSO
Online html documentation available at http://www.netlib.org/lapack/explore-html/
| Nemo Release 3.1 | zhpmv (3) | February 23, 2025 |
