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¶
Note
Refer to Sparse BLAS Supported Data and Integer Types for a list of supported <DATA_TYPE>
and <INT_TYPE>
data
and integer types and refer to Error Handling for a detailed description of
the possible exceptions thrown.
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 \(A\) defined as
where \(\alpha\) and \(\beta\) are scalars, \(A\) is a real-valued square sparse matrix
of dimension \(m\) rows and columns, \(\text{sym}()\) is a matrix modifier which symmetrizes
the matrix according to the oneapi::mkl::uplo
value and \(x\) and \(y\) are dense vectors.
For a given matrix decomposition into lower, diagonal and upper parts \(A = L+D+U\),
the symv
routine with oneapi::mkl::uplo::lower
selected will perform the
matrix product with \(\text{sym}(A) = L+D+L^T\) and for oneapi::mkl::uplo::upper
will
perform the matrix product using \(\text{sym}(A) = U^T+D+U\).
API¶
Syntax¶
Note
Currently, complex types are not supported.
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, \(\alpha\).
- 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, \(m\), of input matrix.
- beta
Specifies the scalar, \(\beta\).
- y
SYCL buffer or device-accessible USM pointer of size at least equal to the number of rows, \(m\), of the input matrix.
- dependencies
A vector of type
std::vector<sycl::event>
containing the list of events that theoneapi::mkl::sparse::symv
routine depends on.
Output Parameters¶
- y
Overwritten by the updated vector \(y\).
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.