Documentation for `cub::DeviceSpmv` refers to unused `alpha` and `beta` parameters

[WeiqunZhang]

There is some inconsistency in the documentation for cub::DeviceSpmv (https://nvlabs.github.io/cub/structcub_1_1_device_spmv.html). The overview says

The SpMV computation performs the matrix-vector operation y = alpha*A*x + beta*y,

But the function signature of CsrMV has neither alpha nor beta, and the function's description says

This function performs the matrix-vector operation y = A*x

However, the code snippet has alpha and beta.

cub::DeviceSpmv::CsrMV(d_temp_storage, temp_storage_bytes, d_values,
    d_row_offsets, d_column_indices, d_vector_x, d_vector_y,
    num_rows, num_cols, num_nonzeros, alpha, beta);

Could someone clarify on this? Thanks!

[alliepiper]

Thanks for reporting this! This should be fixed for the next release.

You are correct, the DeviceSPMV function does not expose the alpha/beta parameters, they are fixed to 1 and 0 respectively.