mkl_?csrsv

Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

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ID 766686

Date 11/07/2023

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mkl_?csrsv

Solves a system of linear equations for a sparse matrix in the CSR format (deprecated).

Syntax

call mkl_scsrsv(transa, m, alpha, matdescra, val, indx, pntrb, pntre, x, y)

call mkl_dcsrsv(transa, m, alpha, matdescra, val, indx, pntrb, pntre, x, y)

call mkl_ccsrsv(transa, m, alpha, matdescra, val, indx, pntrb, pntre, x, y)

call mkl_zcsrsv(transa, m, alpha, matdescra, val, indx, pntrb, pntre, x, y)

Include Files

mkl.fi

Description

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

The mkl_?csrsv routine solves a system of linear equations with matrix-vector operations for a sparse matrix in the CSR 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 a CSR format both with one-based indexing and zero-based indexing.

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 columns of the matrix A.

alpha

REAL for mkl_scsrsv.

DOUBLE PRECISION for mkl_dcsrsv.

COMPLEX for mkl_ccsrsv.

DOUBLE COMPLEX for mkl_zcsrsv.

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”.

val

REAL for mkl_scsrsv.

DOUBLE PRECISION for mkl_dcsrsv.

COMPLEX for mkl_ccsrsv.

DOUBLE COMPLEX for mkl_zcsrsv.

Array containing non-zero elements of the matrix A.

For one-based indexing its length is pntre(m) - pntrb(1).

For zero-based indexing its length is pntre(m-1) - pntrb(0).

Refer to values array description in CSR Format for more details.

NOTE:

The non-zero elements of the given row of the matrix must be stored in the same order as they appear in the row (from left to right).

No diagonal element can be omitted from a sparse storage if the solver is called with the non-unit indicator.

indx

INTEGER. Array containing the column indices for each non-zero element of the matrix A.

Its length is equal to length of the val array.

Refer to columns array description in CSR Format for more details.

NOTE:

Column indices must be sorted in increasing order for each row.

pntrb

INTEGER. Array of length m.

For one-based indexing this array contains row indices, such that pntrb(i) - pntrb(1) + 1 is the first index of row i in the arrays val and indx.

For zero-based indexing this array contains row indices, such that pntrb(i) - pntrb(0) is the first index of row i in the arrays val and indx.

Refer to pointerb array description in CSR Format for more details.

pntre

INTEGER. Array of length m.

For one-based indexing this array contains row indices, such that pntre(i) - pntrb(1) is the last index of row i in the arrays val and indx.

For zero-based indexing this array contains row indices, such that pntre(i) - pntrb(0) - 1 is the last index of row i in the arrays val and indx.

Refer to pointerE array description in CSR Format for more details.

x

REAL for mkl_scsrsv.

DOUBLE PRECISION for mkl_dcsrsv.

COMPLEX for mkl_ccsrsv.

DOUBLE COMPLEX for mkl_zcsrsv.

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_scsrsv.

DOUBLE PRECISION for mkl_dcsrsv.

COMPLEX for mkl_ccsrsv.

DOUBLE COMPLEX for mkl_zcsrsv.

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_scsrsv(transa, m, alpha, matdescra, val, indx, pntrb, pntre, x, y)

  CHARACTER*1   transa

  CHARACTER     matdescra(*)

  INTEGER       m

  INTEGER       indx(*), pntrb(m), pntre(m)

  REAL          alpha

  REAL          val(*)

  REAL          x(*), y(*)

SUBROUTINE mkl_dcsrsv(transa, m, alpha, matdescra, val, indx, pntrb, pntre, x, y)

  CHARACTER*1   transa

  CHARACTER     matdescra(*)

  INTEGER       m

  INTEGER       indx(*), pntrb(m), pntre(m)

  DOUBLE PRECISION        alpha

  DOUBLE PRECISION        val(*)

  DOUBLE PRECISION        x(*), y(*)

SUBROUTINE mkl_ccsrsv(transa, m, alpha, matdescra, val, indx, pntrb, pntre, x, y)

  CHARACTER*1   transa

  CHARACTER     matdescra(*)

  INTEGER       m

  INTEGER       indx(*), pntrb(m), pntre(m)

  COMPLEX        alpha

  COMPLEX        val(*)

  COMPLEX        x(*), y(*)

SUBROUTINE mkl_zcsrsv(transa, m, alpha, matdescra, val, indx, pntrb, pntre, x, y)

  CHARACTER*1   transa

  CHARACTER     matdescra(*)

  INTEGER       m

  INTEGER       indx(*), pntrb(m), pntre(m)

  DOUBLE COMPLEX        alpha

  DOUBLE COMPLEX        val(*)

  DOUBLE COMPLEX        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_?csrsv

Syntax

Include Files

Description

Input Parameters

Output Parameters

Interfaces

FORTRAN 77: