Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

ID 766686
Date 7/13/2023
Public

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mkl_sparse_?_qr_rsolve

Second stage of the solving step of the SPARSE QR solver.

Syntax

stat = mkl_sparse_d_qr_rsolve (operation, A, layout, x, columns, ldx, b, ldb)

stat = mkl_sparse_s_qr_rsolve (operation, A, layout, x, columns, ldx, b, ldb)

Include Files

  • mkl_sparse_qr.f90

Description

The mkl_sparse_?_qr_rsolve routine computes the solution of A*x = b.

NOTE:
Currently, mkl_sparse_?_qr_rsolve supports only CSR format for the input matrix, non-transpose operation, and single right-hand side.

Input Parameters

operation

C_INT

Specifies the operation to perform.

NOTE:
Currently, the only supported value is SPARSE_OPERATION_NON_TRANSPOSE (non-transpose case; that is, A*x = b is solved).
A

SPARSE_MATRIX_T

Handle containing a sparse matrix in an internal data structure.

layout

C_INT

Describes the storage scheme for the dense matrix:

SPARSE_LAYOUT_COLUMN_MAJOR Storage of elements uses column-major layout.
SPARSE_LAYOUT_ROW_MAJOR Storage of elements uses row-major layout.
x

C_FLOAT for mkl_sparse_s_qr; C_DOUBLE for mkl_sparse_d_qr

Array with a size of at least rows*cols:

  layout = SPARSE_LAYOUT_COLUMN_MAJOR layout = SPARSE_LAYOUT_ROW_MAJOR
rows (number of rows in x) ldx Number of columns in A
cols (number of columns in x) columns ldx
columns

C_INT

Number of columns in matrix b.

ldx

C_INT

Specifies the leading dimension of matrix x.

b

C_FLOAT for mkl_sparse_s_qr; C_DOUBLE for mkl_sparse_d_qr

Array with a size of at least rows*cols:

  layout = SPARSE_LAYOUT_COLUMN_MAJOR layout = SPARSE_LAYOUT_ROW_MAJOR
rows (number of rows in b) ldb Number of columns in A
cols (number of columns in b) columns ldb
ldb

C_INT

Specifies the leading dimension of matrix b.

Output Parameters

x

C_FLOAT for mkl_sparse_s_qr; C_DOUBLE for mkl_sparse_d_qr

Contains the solution of the triangular system R*x = b.

stat

INTEGER

Value indicating whether the operation was successful, and if not, why:

SPARSE_STATUS_SUCCESS The operation was successful.
SPARSE_STATUS_NOT_INITIALIZED The routine encountered an empty handle or matrix array.
SPARSE_STATUS_ALLOC_FAILED Internal memory allocation failed.
SPARSE_STATUS_INVALID_VALUE The input parameters contain an invalid value.
SPARSE_STATUS_EXECUTION_FAILED Execution failed.
SPARSE_STATUS_INTERNAL_ERROR An error in algorithm implementation occurred.
SPARSE_STATUS_NOT_SUPPORTED The requested operation is not supported.