CUDA tridiagonal solver function (cusparse)

Question

In my CUDA code I am using cusparse<t>gtsv() function (more precisely, cusparseZgtsv and cusparseZgtsvStridedBatch ones).

In the documentaion it is said, that this function solves the equation A*x=alpha *B. My question is - what is alpha? I didn't find it as an input parameter. I have no idea how to specify it. Is it always equals to 1?

Answer 1

I performed some testing (solved some random systems of equations where tridiagonal matrices were always diagonally dominant and checked my solution using direct matrix by vector multiplication). It looks like in the current version alpha = 1 always, so one can just ignore it. I suspect that it will be added as an input parameter in future releases.