Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

ID 766686
Date 7/13/2023
Public

A newer version of this document is available. Customers should click here to go to the newest version.

Document Table of Contents

mkl_?cscsv

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

Syntax

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

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

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

call mkl_zcscsv(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_?cscsv routine solves a system of linear equations with matrix-vector operations for a sparse matrix in the CSC format:

y := alpha*inv(A)*x

or

y := alpha*inv(AT)* 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, AT is the transpose of A.

NOTE:

This routine supports a CSC 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 operation.

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

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

m

INTEGER. Number of columns of the matrix A.

alpha

REAL for mkl_scscsv.

DOUBLE PRECISION for mkl_dcscsv.

COMPLEX for mkl_ccscsv.

DOUBLE COMPLEX for mkl_zcscsv.

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_scscsv.

DOUBLE PRECISION for mkl_dcscsv.

COMPLEX for mkl_ccscsv.

DOUBLE COMPLEX for mkl_zcscsv.

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 CSC 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 row 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 CSC Format for more details.

NOTE:

Row indices must be sorted in increasing order for each column.

pntrb

INTEGER. Array of length m.

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

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

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

pntre

INTEGER. Array of length m.

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

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

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

x

REAL for mkl_scscsv.

DOUBLE PRECISION for mkl_dcscsv.

COMPLEX for mkl_ccscsv.

DOUBLE COMPLEX for mkl_zcscsv.

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_scscsv.

DOUBLE PRECISION for mkl_dcscsv.

COMPLEX for mkl_ccscsv.

DOUBLE COMPLEX for mkl_zcscsv.

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 the solution vector x.

Interfaces

FORTRAN 77:

SUBROUTINE mkl_scscsv(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_dcscsv(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_ccscsv(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_zcscsv(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(*)