Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

ID 766686
Date 12/16/2022
Public

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mkl_?bsrsv

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

Syntax

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

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

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

call mkl_zbsrsv(transa, m, lb, 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 Inspector-executor Sparse BLAS interface instead.

The mkl_?bsrsv routine solves a system of linear equations with matrix-vector operations for a sparse matrix in the BSR 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 BSR 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 block columns of the matrix A.

lb

INTEGER. Size of the block in the matrix A.

alpha

REAL for mkl_sbsrsv.

DOUBLE PRECISION for mkl_dbsrsv.

COMPLEX for mkl_cbsrsv.

DOUBLE COMPLEX for mkl_zbsrsv.

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_sbsrsv.

DOUBLE PRECISION for mkl_dbsrsv.

COMPLEX for mkl_cbsrsv.

DOUBLE COMPLEX for mkl_zbsrsv.

Array containing elements of non-zero blocks of the matrix A. Its length is equal to the number of non-zero blocks in the matrix A multiplied by lb*lb.

Refer to the values array description in BSR 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 block in the matrix A.

Its length is equal to the number of non-zero blocks in the matrix A.

Refer to the columns array description in BSR Format for more details.

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 block row i in the array indx.

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

Refer to pointerB array description in BSR 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 block row i in the array indx.

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

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

x

REAL for mkl_sbsrsv.

DOUBLE PRECISION for mkl_dbsrsv.

COMPLEX for mkl_cbsrsv.

DOUBLE COMPLEX for mkl_zbsrsv.

Array, size at least (m*lb).

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

y

REAL for mkl_sbsrsv.

DOUBLE PRECISION for mkl_dbsrsv.

COMPLEX for mkl_cbsrsv.

DOUBLE COMPLEX for mkl_zbsrsv.

Array, size at least (m*lb).

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_sbsrsv(transa, m, lb, alpha, matdescra, val, indx, pntrb, pntre, x, y)
  CHARACTER*1   transa
  CHARACTER     matdescra(*)
  INTEGER       m, lb
  INTEGER       indx(*), pntrb(m), pntre(m)
  REAL          alpha
  REAL          val(*)
  REAL          x(*), y(*)

SUBROUTINE mkl_dbsrsv(transa, m, lb, alpha, matdescra, val, indx, pntrb, pntre, x, y)
  CHARACTER*1   transa
  CHARACTER     matdescra(*)
  INTEGER       m, lb
  INTEGER       indx(*), pntrb(m), pntre(m)
  DOUBLE PRECISION        alpha
  DOUBLE PRECISION        val(*)
  DOUBLE PRECISION        x(*), y(*)

SUBROUTINE mkl_cbsrsv(transa, m, lb, alpha, matdescra, val, indx, pntrb, pntre, x, y)
  CHARACTER*1   transa
  CHARACTER     matdescra(*)
  INTEGER       m, lb
  INTEGER       indx(*), pntrb(m), pntre(m)
  COMPLEX        alpha
  COMPLEX        val(*)
  COMPLEX        x(*), y(*)

SUBROUTINE mkl_zbsrsv(transa, m, lb, alpha, matdescra, val, indx, pntrb, pntre, x, y)
  CHARACTER*1   transa
  CHARACTER     matdescra(*)
  INTEGER       m, lb
  INTEGER       indx(*), pntrb(m), pntre(m)
  DOUBLE COMPLEX        alpha
  DOUBLE COMPLEX        val(*)
  DOUBLE COMPLEX        x(*), y(*)