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Visible to Intel only — GUID: GUID-5D008399-4B80-4C0D-B3A8-8E8EE83BEDA4
Visible to Intel only — GUID: GUID-5D008399-4B80-4C0D-B3A8-8E8EE83BEDA4
oneapi::mkl::sparse::symv
Computes a sparse matrix-dense vector product for a symmetric matrix built from the lower or upper triangular of the input matrix.
Description
The oneapi::mkl::sparse::symv routine computes a sparse symmetric matrix-dense vector product for a real symmetric matrix built from the lower or upper triangular portion of the input matrix 
defined as
where 
and 
are scalars, is a real-valued square sparse matrix of dimension 
rows and columns, 
is a matrix modifier which symmetrizes the matrix according to the oneapi::mkl::uplo value and 
and 
are dense vectors.
For a given matrix decomposition into lower, diagonal and upper parts 
, the symv routine with oneapi::mkl::uplo::lower selected will perform the matrix product with 
and for oneapi::mkl::uplo::upper will perform the matrix product using 
.
API
Syntax
Using SYCL buffers:
namespace oneapi::mkl::sparse { void symv ( sycl::queue &queue, oneapi::mkl::uplo uplo_val, const DATA_TYPE alpha, oneapi::mkl::sparse::matrix_handle_t A, sycl::buffer<DATA_TYPE, 1> &x, const DATA_TYPE beta, sycl::buffer<DATA_TYPE, 1> &y) }
Using USM pointers:
namespace oneapi::mkl::sparse { sycl::event symv ( sycl::queue &queue, oneapi::mkl::uplo uplo_val, const DATA_TYPE alpha, oneapi::mkl::sparse::matrix_handle_t A, const DATA_TYPE *x, const DATA_TYPE beta, DATA_TYPE *y, const std::vector<sycl::event> &dependencies = {}) }
Include Files
oneapi/mkl/spblas.hpp
Input Parameters
- queue
-
Specifies the SYCL command queue which will be used for SYCL kernels execution.
- uplo_val
-
Specifies which part is to be processed.
oneapi::mkl::uplo::lower
The lower part is used for symmetric product.
oneapi::mkl::uplo::upper
The upper part is used for symmetric product.
- alpha
-
Specifies the scalar,
. - A
-
Handle to object containing sparse matrix and other internal data. Created using one of the oneapi::mkl::sparse::set_<sparse_matrix_type>_data routines.
NOTE:Currently, the only supported case for <sparse_matrix_type> is csr. - x
-
SYCL buffer or device-accessible USM pointer of size at least equal to the number of columns,
, of input matrix. - beta
-
Specifies the scalar,
. - y
-
SYCL buffer or device-accessible USM pointer of size at least equal to the number of rows,
, of the input matrix. - dependencies
-
A vector of type std::vector<sycl::event> containing the list of events that the oneapi::mkl::sparse::symv routine depends on.
Output Parameters
- y
-
Overwritten by the updated vector
.
Return Values (USM Only)
- sycl::event
-
SYCL event which can be waited upon or added as a dependency for the completion of the symv routine.
Examples
An example of how to use oneapi::mkl::sparse::symv with SYCL buffers can be found in the oneMKL installation directory, under:
share/doc/mkl/examples/sycl/sparse_blas/source/csr_symv.cpp