Great work Dmitry! It's superb that we now have a general purpose N-dimensional array implementation that is comparable with NumPy, written in pure Clojure. This will be a big boost for people doing data science / scientific computing with Clojure.
You've also shown that it's possible to write some pretty high performance numerical code in Clojure (with a bit of macro magic, of course!) On Tuesday, 24 September 2013 05:25:25 UTC+8, Dmitry Groshev wrote: > > Today Google Summer of Code finally ends. NDArray is pretty stable now and > will be the default implementation used by core.matrix in the upcoming > release. It was an epic journey through bugs, unexpected slowness and weird > macros, but now I can proudly state that in some cases NDArray can be > faster than NumPy by a factor of two: [1]. > > Well, not always. It's hard to consistently beat highly optimized and > vectorized native code on JVM :) But we have a secrete sauce here in > Clojure: macros. You can find the code I've benchmarked here: [2]. What's > going on? The thing here is that using macros we can fully eliminate the > cost of intermediate matrix allocation (or function call machinery in case > of map-like functions) doing element-wise operations. Thanks to macros, the > code will be expanded to a highly optimized loop right inside user's code, > hiding messy details of NDArray and Clojure's type hinting from user, but > exposing necessary information to JVM. Moreover, this will work on a bunch > of NDArrays, too: [3]. More details can be found in NDArray's documentation > (by the courtesy of Marginalia): [4]. > > Overall, this project was very interesting experience to me. Hope others > will find it useful :) > > Cheers! > Dmitry > > [1]: http://i.imgur.com/6qdUF7f.png > [2]: https://gist.github.com/si14/6676599 > [3]: > https://github.com/mikera/matrix-api/blob/develop/src/test/clojure/clojure/core/matrix/test_ndarray_implementation.clj#L16 > [4]: http://mikera.github.io/matrix-api/ndarray.html > -- -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
