Visible to Intel only — GUID: GUID-7185705A-510E-430B-B8DC-80FFFCAD9824
Visible to Intel only — GUID: GUID-7185705A-510E-430B-B8DC-80FFFCAD9824
?spmv
Computes a matrix-vector product for complex vectors using a complex symmetric packed matrix.
Syntax
call cspmv( uplo, n, alpha, ap, x, incx, beta, y, incy )
call zspmv( uplo, n, alpha, ap, x, incx, beta, y, incy )
Include Files
- mkl.fi
Description
The ?spmv routines perform a matrix-vector operation defined as
y := alpha*a*x + beta*y,
where:
alpha and beta are complex scalars,
x and y are n-element complex vectors
a is an n-by-n complex symmetric matrix, supplied in packed form.
These routines have their real equivalents in BLAS (see ?spmv in Chapter "BLAS and Sparse BLAS Routines").
Input Parameters
- uplo
-
CHARACTER*1. Specifies whether the upper or lower triangular part of the matrix a is supplied in the packed array ap.
If uplo = 'U' or 'u', the upper triangular part of the matrix a is supplied in the array ap.
If uplo = 'L' or 'l', the lower triangular part of the matrix a is supplied in the array ap .
- n
-
INTEGER.
Specifies the order of the matrix a.
The value of n must be at least zero.
- alpha, beta
-
COMPLEX for cspmv
DOUBLE COMPLEX for zspmv
Specify complex scalars alpha and beta. When beta is supplied as zero, then y need not be set on input.
- ap
-
COMPLEX for cspmv
DOUBLE COMPLEX for zspmv
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 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 = 'L' or 'l', 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.
- x
-
COMPLEX for cspmv
DOUBLE COMPLEX for zspmv
Array, DIMENSION at least (1 + (n - 1)*abs(incx)). Before entry, the incremented array x must contain the n-element vector x.
- incx
-
INTEGER. Specifies the increment for the elements of x. The value of incx must not be zero.
- y
-
COMPLEX for cspmv
DOUBLE COMPLEX for zspmv
Array, DIMENSION at least (1 + (n - 1)*abs(incy)). Before entry, the incremented array y must contain the n-element vector y.
- incy
-
INTEGER. Specifies the increment for the elements of y. The value of incy must not be zero.
Output Parameters
- y
-
Overwritten by the updated vector y.