mkl_sparse_?_qr

Solving step of the SPARSE QR solver.

Syntax

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

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

Include Files

mkl_sparse_qr.f90

Description

The mkl_sparse_?_qr_solve routine computes the solution of sparse systems of linear equations A*x = b. Prior to calling this routine, the mkl_sparse_?_qr_factorize routine must be called for the matrix handle A. For more information about the workflow of sparse QR functionality, refer to oneMKL Sparse QR solver. Multifrontal Sparse QR Factorization Method for Solving a Sparse System of Linear Equations.

Note

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

Alternative values are not supported and must be set to NULL.

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.

alt_values

C_FLOAT for mkl_sparse_s_qr_solve; C_DOUBLE for mkl_sparse_d_qr_solve

Reserved for future use.

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 system A*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.