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oneapi::mkl::sparse::trsv

Solves a system of linear equations for a triangular sparse matrix.

Description

Refer to Supported Types for a list of supported
<fp>
and
<intType>
, and refer to Exceptions for a detailed description of the exceptions thrown.
The
oneapi::mkl::sparse::trsv
routine solves the sparse triangular system
LaTex Math image.
where LaTex Math image. is a sparse triangular matrix of size LaTex Math image. rows by LaTex Math image. columns and LaTex Math image. is a matrix modifier:
LaTex Math image.
The dense vectors LaTex Math image. and LaTex Math image. should be of length at least LaTex Math image.. The vector LaTex Math image. is input right hand side data and math:
y
is the resulting output vector.
For a given matrix decomposition into lower, diagonal and upper parts LaTex Math image., the triangular solve with one of
oneapi::mkl::uplo::lower
or
oneapi::mkl::uplo::upper
selected will perform the appropriate forward or backward substitution using respectively LaTex Math image. or LaTex Math image. for
oneapi::mkl::diag::nonunit
or if using
oneapi::mkl::diag::unit
, will perform the appropriate forward or backward substitution for LaTex Math image. or LaTex Math image. where LaTex Math image. is the identity matrix.

API

Syntax
Currently, complex types are not supported.
Using SYCL buffers:
namespace oneapi::mkl::sparse { void trsv ( cl::sycl::queue &queue, oneapi::mkl::uplo uplo_flag, oneapi::mkl::transpose transpose_flag, oneapi::mkl::diag diag_flag, oneapi::mkl::sparse::matrix_handle_t handle, cl::sycl::buffer<fp, 1> &x, cl::sycl::buffer<fp, 1> &y) }
Using USM pointers:
namespace oneapi::mkl::sparse { cl::sycl::event trsv( cl::sycl::queue &queue, oneapi::mkl::uplo uplo_flag, oneapi::mkl::transpose transpose_flag, oneapi::mkl::diag diag_flag, oneapi::mkl::sparse::matrix_handle_t handle, fp *x, fp *y, const std::vector<cl::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 of the matrix is to be processed.
oneapi::mkl::uplo::lower
The lower triangular matrix part is processed.
oneapi::mkl::uplo::upper
The upper triangular matrix part is processed.
transpose_flag
Specifies operation
op()
on input matrix.
oneapi::mkl::transpose::nontrans
Non-transpose, LaTex Math image..
oneapi::mkl::transpose::trans
Transpose, LaTex Math image..
oneapi::mkl::transpose::conjtrans
Conjugate transpose, LaTex Math image..
Currently, the only supported case for operation is
oneapi::mkl::transpose::nontrans
.
diag_flag
Specifies if the diagonal used for computations is unit or based on provided matrix data.
oneapi::mkl::diag::nonunit
Diagonal elements are used as provided in the sparse matrix.
oneapi::mkl::diag::unit
The value of one is substituted for the diagonal elements in the triangular solve algorithm.
If
oneapi::mkl::diag::nonunit
is selected, all diagonal values must be present in the sparse matrix. This is not necessary for the
oneapi::mkl::diag::unit
case.
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.
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 if
transpose_flag
=
oneapi::mkl::transpose::nontrans
and at least the number of rows of input matrix otherwise. It is the input vector
x
dependencies
A vector of type
std::vector<cl::sycl::event>
containing the list of events that the
oneapi::mkl::sparse::trsv
routine depends on.
Output Parameters
y
SYCL buffer or device-accessible USM pointer of size at least equal to the number of rows of the input matrix if
transpose_flag
=
oneapi::mkl::transpose::nontrans
and at least the number of columns of the input matrix otherwise. The solution of the triangular solve is filled into this array.
Return Values (USM Only)
cl::sycl::event
SYCL event which can be waited upon or added as a dependency for the completion of the
trsv
routine.

Examples

An example of how to use
oneapi::mkl::sparse::trsv
with SYCL buffers or USM can be found in the oneMKL installation directory, under:
examples/dpcpp/sparse_blas/source/sparse_trsv.cpp
examples/dpcpp/sparse_blas/source/sparse_trsv_usm.cpp

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.