mkl_?skysv

Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

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ID 766686

Date 3/31/2023

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mkl_?skysv

Solves a system of linear equations for a sparse matrix in the skyline format with one-based indexing (deprecated).

Syntax

call mkl_sskysv(transa, m, alpha, matdescra, val, pntr, x, y)

call mkl_dskysv(transa, m, alpha, matdescra, val, pntr, x, y)

call mkl_cskysv(transa, m, alpha, matdescra, val, pntr, x, y)

call mkl_zskysv(transa, m, alpha, matdescra, val, pntr, x, y)

Include Files

mkl.fi

Description

This routine is deprecated. Use mkl_sparse_?_trsvfrom the Intel® oneAPI Math Kernel Library Inspector-executor Sparse BLAS interface instead.

The mkl_?skysv routine solves a system of linear equations with matrix-vector operations for a sparse matrix in the skyline storage format:

y := alpha*inv(A)*x

y := alpha*inv(A^T)*x,

where:

alpha is scalar, x and y are vectors, A is a sparse upper or lower triangular matrix with unit or non-unit main diagonal, A^T is the transpose of A.

NOTE:

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

Input Parameters

Parameter descriptions are common for all implemented interfaces with the exception of data types that refer here to the FORTRAN 77 standard types. Data types specific to the different interfaces are described in the section "Interfaces" below.

transa

CHARACTER*1. Specifies the system of linear equations.

If transa = 'N' or 'n', then y := alpha*inv(A)*x

If transa = 'T' or 't' or 'C' or 'c', then y := alpha*inv(A^T)* x,

m

INTEGER. Number of rows of the matrix A.

alpha

REAL for mkl_sskysv.

DOUBLE PRECISION for mkl_dskysv.

COMPLEX for mkl_cskysv.

DOUBLE COMPLEX for mkl_zskysv.

Specifies the scalar alpha.

matdescra

CHARACTER. 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(1)='G') is not supported.

val

REAL for mkl_sskysv.

DOUBLE PRECISION for mkl_dskysv.

COMPLEX for mkl_cskysv.

DOUBLE COMPLEX for mkl_zskysv.

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

If matdescra(2)= 'L', then val contains elements from the low triangle of the matrix A.

If matdescra(2)= '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

INTEGER. 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

REAL for mkl_sskysv.

DOUBLE PRECISION for mkl_dskysv.

COMPLEX for mkl_cskysv.

DOUBLE COMPLEX for mkl_zskysv.

Array, size at least m.

On entry, the array x must contain the vector x. The elements are accessed with unit increment.

y

REAL for mkl_sskysv.

DOUBLE PRECISION for mkl_dskysv.

COMPLEX for mkl_cskysv.

DOUBLE COMPLEX for mkl_zskysv.

Array, size at least m.

On entry, the array y must contain the vector y. The elements are accessed with unit increment.

Output Parameters

y: Contains solution vector x.

Interfaces

FORTRAN 77:

SUBROUTINE mkl_sskysv(transa, m, alpha, matdescra, val, pntr, x, y)

  CHARACTER*1   transa

  CHARACTER     matdescra(*)

  INTEGER       m

  INTEGER       pntr(*)

  REAL        alpha

  REAL        val(*), x(*), y(*)

SUBROUTINE mkl_dskysv(transa, m, alpha, matdescra, val, pntr, x, y)

  CHARACTER*1   transa

  CHARACTER     matdescra(*)

  INTEGER       m

  INTEGER       pntr(*)

  DOUBLE PRECISION        alpha

  DOUBLE PRECISION        val(*), x(*), y(*)

SUBROUTINE mkl_cskysv(transa, m, alpha, matdescra, val, pntr, x, y)

  CHARACTER*1   transa

  CHARACTER     matdescra(*)

  INTEGER       m

  INTEGER       pntr(*)

  COMPLEX        alpha

  COMPLEX        val(*), x(*), y(*)

SUBROUTINE mkl_zskysv(transa, m, alpha, matdescra, val, pntr, x, y)

  CHARACTER*1   transa

  CHARACTER     matdescra(*)

  INTEGER       m

  INTEGER       pntr(*)

  DOUBLE COMPLEX        alpha

  DOUBLE COMPLEX        val(*), x(*), y(*)

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

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Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

mkl_?skysv

FORTRAN 77: