Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

ID 766686
Date 3/22/2024
Public

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mkl_?skysm

Solves a system of linear matrix equations for a sparse matrix stored using the skyline storage scheme with one-based indexing (deprecated).

Syntax

call mkl_sskysm(transa, m, n, alpha, matdescra, val, pntr, b, ldb, c, ldc)

call mkl_dskysm(transa, m, n, alpha, matdescra, val, pntr, b, ldb, c, ldc)

call mkl_cskysm(transa, m, n, alpha, matdescra, val, pntr, b, ldb, c, ldc)

call mkl_zskysm(transa, m, n, alpha, matdescra, val, pntr, b, ldb, c, ldc)

Include Files

  • mkl.fi

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_?skysm routine solves a system of linear equations with matrix-matrix operations for a sparse matrix in the skyline storage format:

C := alpha*inv(A)*B

or

C := alpha*inv(AT)*B,

where:

alpha is scalar, B and C are dense matrices, A is a sparse upper or lower triangular matrix with unit or non-unit main diagonal, AT 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 C := alpha*inv(A)*B,

If transa = 'T' or 't' or 'C' or 'c', then C := alpha*inv(AT)*B,

m

INTEGER. Number of rows of the matrix A.

n

INTEGER. Number of columns of the matrix C.

alpha

REAL for mkl_sskysm.

DOUBLE PRECISION for mkl_dskysm.

COMPLEX for mkl_cskysm.

DOUBLE COMPLEX for mkl_zskysm.

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_sskysm.

DOUBLE PRECISION for mkl_dskysm.

COMPLEX for mkl_cskysm.

DOUBLE COMPLEX for mkl_zskysm.

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

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

If matdescrsa(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 (n + 1) for upper triangle.

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

b

REAL for mkl_sskysm.

DOUBLE PRECISION for mkl_dskysm.

COMPLEX for mkl_cskysm.

DOUBLE COMPLEX for mkl_zskysm.

Array, size (ldb, n).

On entry the leading m-by-n part of the array b must contain the matrix B.

ldb

INTEGER. Specifies the leading dimension of b as declared in the calling (sub)program.

ldc

INTEGER. Specifies the leading dimension of c as declared in the calling (sub)program.

Output Parameters

c

REAL for mkl_sskysm.

DOUBLE PRECISION for mkl_dskysm.

COMPLEX for mkl_cskysm.

DOUBLE COMPLEX for mkl_zskysm.

Array, size ldc by n.

The leading m-by-n part of the array c contains the matrix C.

Interfaces

FORTRAN 77:

 

SUBROUTINE mkl_sskysm(transa, m, n, alpha, matdescra, val, pntr, b, ldb, c, ldc)
  CHARACTER*1   transa
  CHARACTER     matdescra(*)
  INTEGER       m, n, ldb, ldc
  INTEGER       pntr(*)
  REAL          alpha
  REAL          val(*), b(ldb,*), c(ldc,*)

SUBROUTINE mkl_dskysm(transa, m, n, alpha, matdescra, val, pntr, b, ldb, c, ldc)
  CHARACTER*1   transa
  CHARACTER     matdescra(*)
  INTEGER       m, n, ldb, ldc
  INTEGER       pntr(*)
  DOUBLE PRECISION        alpha
  DOUBLE PRECISION        val(*), b(ldb,*), c(ldc,*)

SUBROUTINE mkl_cskysm(transa, m, n, alpha, matdescra, val, pntr, b, ldb, c, ldc)
  CHARACTER*1   transa
  CHARACTER     matdescra(*)
  INTEGER       m, n, ldb, ldc
  INTEGER       pntr(*)
  COMPLEX        alpha
  COMPLEX        val(*), b(ldb,*), c(ldc,*)

SUBROUTINE mkl_zskysm(transa, m, n, alpha, matdescra, val, pntr, b, ldb, c, ldc)
  CHARACTER*1   transa
  CHARACTER     matdescra(*)
  INTEGER       m, n, ldb, ldc
  INTEGER       pntr(*)
  DOUBLE COMPLEX        alpha
  DOUBLE COMPLEX        val(*), b(ldb,*), c(ldc,*)