Sparse matrix vector multiplication.

rocsparse_spmv multiplies the scalar $\alpha$ with a sparse $m \times n$ matrix and the dense vector $x$ and adds the result to the dense vector $y$ that is multiplied by the scalar $\beta$, such that

$$y := \alpha \cdot op(A) \cdot x + \beta \cdot y,$$

with

$$op(A) = \left\{ \begin{array}{ll} A, & \text{if trans == rocsparse_operation_none} \newline A^T, & \text{if trans == rocsparse_operation_transpose} \newline A^H, & \text{if trans == rocsparse_operation_conjugate_transpose} \end{array} \right.$$

Note

This function writes the required allocation size (in bytes) to buffer_size and returns without performing the SpMV operation, when a nullptr is passed for temp_buffer.

This function is non blocking and executed asynchronously with respect to the host. It may return before the actual computation has finished.

Parameters

[in]	handle	handle to the rocsparse library context queue.
[in]	trans	matrix operation type.
[in]	alpha	scalar $\alpha$.
[in]	mat	matrix descriptor.
[in]	x	vector descriptor.
[in]	beta	scalar $\beta$.
[in,out]	y	vector descriptor.
[in]	compute_type	floating point precision for the SpMV computation.
[in]	alg	SpMV algorithm for the SpMV computation.
[out]	buffer_size	number of bytes of the temporary storage buffer. buffer_size is set when temp_buffer is nullptr.
[in]	temp_buffer	temporary storage buffer allocated by the user. When a nullptr is passed, the required allocation size (in bytes) is written to buffer_size and function returns without performing the SpMV operation.

Return values

rocsparse_status_success	the operation completed successfully.
rocsparse_status_invalid_handle	the library context was not initialized.
rocsparse_status_invalid_pointer	alpha, mat, x, beta, y or buffer_size pointer is invalid.
rocsparse_status_not_implemented	compute_type or alg is currently not supported.