CSYMV (3) Linux Manual Page

csymv.f –

Synopsis

Functions/Subroutines

subroutine csymv (UPLO, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY)
CSYMV computes a matrix-vector product for a complex symmetric matrix.

Function/Subroutine Documentation

subroutine csymv (characterUPLO, integerN, complexALPHA, complex, dimension( lda, * )A, integerLDA, complex, dimension( * )X, integerINCX, complexBETA, complex, dimension( * )Y, integerINCY)

CSYMV computes a matrix-vector product for a complex symmetric matrix.

Purpose:

 CSYMV 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 symmetric matrix.

 

Parameters:

UPLO

 UPLO is CHARACTER*1

 On entry, UPLO specifies whether the upper or lower

 triangular part of the array A is to be referenced as

 follows:

 UPLO = ‘U’ or ‘u’ Only the upper triangular part of A

 is to be referenced.

 UPLO = ‘L’ or ‘l’ Only the lower triangular part of A

 is to be referenced.

 Unchanged on exit.

N

 N is INTEGER

 On entry, N specifies the order of the matrix A.

 N must be at least zero.

 Unchanged on exit.

ALPHA

 ALPHA is COMPLEX

 On entry, ALPHA specifies the scalar alpha.

 Unchanged on exit.

A

 A is COMPLEX array, dimension ( LDA, N )

 Before entry, with UPLO = ‘U’ or ‘u’, the leading n by n

 upper triangular part of the array A must contain the upper

 triangular part of the symmetric matrix and the strictly

 lower triangular part of A is not referenced.

 Before entry, with UPLO = ‘L’ or ‘l’, the leading n by n

 lower triangular part of the array A must contain the lower

 triangular part of the symmetric matrix and the strictly

 upper triangular part of A is not referenced.

 Unchanged on exit.

LDA

 LDA is INTEGER

 On entry, LDA specifies the first dimension of A as declared

 in the calling (sub) program. LDA must be at least

 max( 1, N ).

 Unchanged on exit.

X

 X is COMPLEX array, dimension at least

 ( 1 + ( N – 1 )*abs( INCX ) ).

 Before entry, the incremented array X must contain the N-

 element vector x.

 Unchanged on exit.

INCX

 INCX is INTEGER

 On entry, INCX specifies the increment for the elements of

 X. INCX must not be zero.

 Unchanged on exit.

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.

 Unchanged on exit.

Y

 Y is COMPLEX 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.

 Unchanged on exit.

 

Author:

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Date:

September 2012

Definition at line 158 of file csymv.f.

Author

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