cspmv (l)  Linux Man Pages
cspmv: performs the matrixvector operation y := alpha*A*x + beta*y,
Command to display cspmv
manual in Linux: $ man l cspmv
NAME
CSPMV  performs the matrixvector operation y := alpha*A*x + beta*y,
SYNOPSIS
 SUBROUTINE CSPMV(

UPLO, N, ALPHA, AP, X, INCX, BETA, Y, INCY )

CHARACTER
UPLO

INTEGER
INCX, INCY, N

COMPLEX
ALPHA, BETA

COMPLEX
AP( * ), X( * ), Y( * )
PURPOSE
CSPMV performs the matrixvector operation
where alpha and beta are scalars, x and y are n element vectors and
A is an n by n symmetric matrix, supplied in packed form.
ARGUMENTS
 UPLO (input) 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 = aqUaq or aquaq The upper triangular part of A is
supplied in AP.
UPLO = aqLaq or aqlaq The lower triangular part of A is
supplied in AP.
Unchanged on exit.
 N (input) INTEGER

On entry, N specifies the order of the matrix A.
N must be at least zero.
Unchanged on exit.
 ALPHA (input) COMPLEX

On entry, ALPHA specifies the scalar alpha.
Unchanged on exit.
 AP (input) COMPLEX array, dimension at least

( ( N*( N + 1 ) )/2 ).
Before entry, with UPLO = aqUaq or aquaq, the array AP must
contain the upper triangular part of the symmetric 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 = aqLaq or aqlaq, the array AP must
contain the lower triangular part of the symmetric 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.
Unchanged on exit.
 X (input) 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 (input) INTEGER

On entry, INCX specifies the increment for the elements of
X. INCX must not be zero.
Unchanged on exit.
 BETA (input) 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 (input/output) 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 (input) INTEGER

On entry, INCY specifies the increment for the elements of
Y. INCY must not be zero.
Unchanged on exit.
Pages related to cspmv
 cspmv (3)
 cspcon (l)  estimates the reciprocal of the condition number (in the 1norm) of a complex symmetric packed matrix A using the factorization A = U*D*U**T or A = L*D*L**T computed by CSPTRF
 cspr (l)  performs the symmetric rank 1 operation A := alpha*x*conjg( xaq ) + A,
 csprfs (l)  improves the computed solution to a system of linear equations when the coefficient matrix is symmetric indefinite and packed, and provides error bounds and backward error estimates for the solution
 cspsv (l)  computes the solution to a complex system of linear equations A * X = B,
 cspsvx (l)  uses the diagonal pivoting factorization A = U*D*U**T or A = L*D*L**T to compute the solution to a complex system of linear equations A * X = B, where A is an NbyN symmetric matrix stored in packed format and X and B are NbyNRHS matrices
 csptrf (l)  computes the factorization of a complex symmetric matrix A stored in packed format using the BunchKaufman diagonal pivoting method
 csptri (l)  computes the inverse of a complex symmetric indefinite matrix A in packed storage using the factorization A = U*D*U**T or A = L*D*L**T computed by CSPTRF
 csptrs (l)  solves a system of linear equations A*X = B with a complex symmetric matrix A stored in packed format using the factorization A = U*D*U**T or A = L*D*L**T computed by CSPTRF