mkl_?skymv

Developer Reference for Intel® oneAPI Math Kernel Library for C

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ID 766684

Date 3/22/2024

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mkl_?skymv

Computes matrix - vector product for a sparse matrix in the skyline storage format with one-based indexing (deprecated).

Syntax

void mkl_sskymv (const char *transa , const MKL_INT *m , const MKL_INT *k , const float *alpha , const char *matdescra , const float *val , const MKL_INT *pntr , const float *x , const float *beta , float *y );

void mkl_dskymv (const char *transa , const MKL_INT *m , const MKL_INT *k , const double *alpha , const char *matdescra , const double *val , const MKL_INT *pntr , const double *x , const double *beta , double *y );

void mkl_cskymv (const char *transa , const MKL_INT *m , const MKL_INT *k , const MKL_Complex8 *alpha , const char *matdescra , const MKL_Complex8 *val , const MKL_INT *pntr , const MKL_Complex8 *x , const MKL_Complex8 *beta , MKL_Complex8 *y );

void mkl_zskymv (const char *transa , const MKL_INT *m , const MKL_INT *k , const MKL_Complex16 *alpha , const char *matdescra , const MKL_Complex16 *val , const MKL_INT *pntr , const MKL_Complex16 *x , const MKL_Complex16 *beta , MKL_Complex16 *y );

Include Files

mkl.h

Description

This routine is deprecated, but no replacement is available yet in the Inspector-Executor Sparse BLAS API interfaces. You can continue using this routine until a replacement is provided and this can be fully removed.

The mkl_?skymv routine performs a matrix-vector operation defined as

y := alpha*A*x + beta*y

y := alpha*A^T*x + beta*y,

where:

alpha and beta are scalars,

x and y are vectors,

A is an m-by-k sparse matrix stored using the skyline storage scheme, A^T is the transpose of A.

NOTE:

This routine supports only one-based indexing of the input arrays.

Input Parameters

transa

Specifies the operation.

If transa = 'N' or 'n', then y := alpha*A*x + beta*y

If transa = 'T' or 't' or 'C' or 'c', then y := alpha*A^T*x + beta*y,

m

Number of rows of the matrix A.

k

Number of columns of the matrix A.

alpha

Specifies the scalar alpha.

matdescra

Array of six elements, specifies properties of the matrix used for operation. Only first four array elements are used, their possible values are given in Table “Possible Values of the Parameter matdescra (descra)”. Possible combinations of element values of this parameter are given in Table “Possible Combinations of Element Values of the Parameter matdescra”.

NOTE:

General matrices (matdescra[0]='G') is not supported.

val

Array containing the set of elements of the matrix A in the skyline profile form.

If matdescrsa[1]= 'L', then val contains elements from the low triangle of the matrix A.

If matdescrsa[1]= 'U', then val contains elements from the upper triangle of the matrix A.

Refer to values array description in Skyline Storage Scheme for more details.

pntr

Array of length (m + 1) for lower triangle, and (k + 1) for upper triangle.

It contains the indices specifying in the val the positions of the first element in each row (column) of the matrix A. Refer to pointers array description in Skyline Storage Scheme for more details.

x

Array, size at least k if transa = 'N' or 'n' and at least m otherwise. On entry, the array x must contain the vector x.

beta

Specifies the scalar beta.

y

Array, size at least m if transa = 'N' or 'n' and at least k otherwise. On entry, the array y must contain the vector y.

Output Parameters

y: Overwritten by the updated vector y.

Parent topic: Sparse BLAS Level 2 and Level 3 Routines.

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Developer Reference for Intel® oneAPI Math Kernel Library for C

mkl_?skymv

Syntax

Include Files

Description

Input Parameters

Output Parameters