On Jan 28, 7:09 am, Konrad Hinsen <konrad.hin...@laposte.net> wrote: > It is possible to generalize the Fast Multipole Method somewhat, but > it remains a technique for a limited (though important) class of > interactions. It is rather unlikely that it will be of any use for > simulating a flock of birds.
The FMM itself might not be directly applicable to simulating bird flocking, but the general idea of the FMM and similar algorithms (coalesce groups of far-away point forces into a single force) could be helpful. For the n^2 algorithm, it's mainly important to pay attention to data locality. Suppose for example that you keep the n 2-D coordinates of the birds in an n x 2 array. (OP is right, Java multi-D arrays are awful for performance; map this n x 2 array onto a single-D Java array.) So you have L = x_1, y_1 x_2, y_2 ... x_n, y_n Computing the distances is a kind of outer product. For best locality in L, you'll want to store it row-wise rather than column-wise. That way when you iterate over points you'll be traveling with unit stride over L rather than skipping over it by n steps each time. mfh --~--~---------~--~----~------------~-------~--~----~ 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 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 -~----------~----~----~----~------~----~------~--~---
