cluster_sparse_solver_get_csr

Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

Download PDF

ID 766686

Date 4/28/2026

Version

Public

cluster_sparse_solver_get_csr_size

Computes the (local) number of rows and (local) number of nonzero entries for (distributed) CSR data corresponding to the provided name.

Syntax

call cluster_sparse_solver_get_csr_size ( pt , name , local_nrows , local_nnz , comm , error )

Include Files

mkl_cluster_sparse_solver.f90

Description

This routine uses the internal data created during the factorization phase of cluster_sparse_solver for matrix A . The routine then:

Computes the local number of rows and the local number of nonzeros for CSR data that correspond to the provided name
Returns the computed values in local_nrows and local_nnz

It is assumed that the CSR data defined by the name will be distributed in the same way as the matrix A (as defined by iparm[39]iparm(40) ) used in cluster_sparse_solver .

The returned values can be used for allocating CSR arrays for factors L and U , and also for allocating arrays for permutations P and Q , or scaling matrix D which can then be used with cluster_sparse_solver_set_csr_ptrs or cluster_sparse_solver_set_ptr for exporting corresponding data via cluster_sparse_solver_export .

Only call this routine after the factorization phase ( phase=22 ) of the cluster_sparse_solver has been called. Neither pt , nor iparm should be changed after the preceding call to cluster_sparse_solver .

Input Parameters

pt

INTEGER*8 for 64-bit architectures

Array with size of 64. Handle to internal data structure used in the prior calls to cluster_sparse_solver .

name

INTEGER

Specifies CSR data for which the output values are computed.

**CSR Data Specified by :code:`name`**
`SPARSE_PTLUQT_L`	Factor L from `\(P\cdot A \cdot Q = L \cdot U\)`.
`SPARSE_PTLUQT_U`	Factor U from `\(P\cdot A \cdot Q = L \cdot U\)`.
`SPARSE_DPTLUQT_L`	Factor L from `\(P \cdot (D^{-1}A) \cdot Q = L \cdot U\)`.
`SPARSE_DPTLUQT_U`	Factor U from `\(P \cdot (D^{-1}A) \cdot Q = L \cdot U\)`.

local_nrows: On entry, an array of size 1.
local_nnz: On entry, an array of size 1.

comm

INTEGER*4. MPI communicator. The solver uses the Fortran MPI communicator internally.

Output Parameters

local_nrows

INTEGER

On output, the local number of rows for the CSR data which correspond to the name .

local_nnz

INTEGER

On output, the local number of nonzero entries for the CSR data which correspond to the name .

error

INTEGER

The error indicator:

**Error Information**
0	no error
-1	pt is a null pointer
-2	invalid pt
-3	invalid name
-4	unsupported name
-9	unsupported internal code path, consider switching off non-default iparm parameters for `cluster_sparse_solver`
-10	unsupported case when the matrix A is distributed among processes with overlap in the preceding calls to `cluster_sparse_solver`
-12	internal memory error

NOTE:

Refer to cl_solver_export_f90.f90 for an example using this functionality.

Select Your Language

Using Intel.com Search

Quick Links

Recent Searches

Advanced Search

Only search in

Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

cluster_sparse_solver_get_csr_size

Syntax

Include Files

Description

Input Parameters

Output Parameters