@dorab you have many unnecessary conversions and copyings there. for examples of how to use neanderthal, read dragan.rocks articles, articles from http://neanderthal.uncomplicate.org, tests, and for advanced use, you can browse bayadera code. read the docs, measure the perf, and, above all, use common sense.

Thanks @blueberry.

@blueberry Thank you! works for me. will do for now 🙂