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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_flag,
        const DATA_TYPE alpha,
        oneapi::mkl::sparse::matrix_handle_t handle,
        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_flag,
        const DATA_TYPE alpha,
        oneapi::mkl::sparse::matrix_handle_t handle,
        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_flag
 -  
     
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,
. - handle
 -  
     
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:
examples/dpcpp/sparse_blas/source/sparse_symv.cpp