On 21 February 2017 at 13:23, Joe Bogner <joebog...@gmail.com> wrote: >> >> The key thing here is that I'm going to be collecting millions of >> results, and I'll run out of memory if I just retain them all and >> count at the end. But I'm not sure how to modify structures in J. >> > > Are you sure you will run out of memory? I can hold a billion ints on my > machine and use 7.8gb of memory.
I did yesterday. I can't recall the details - I may have been running a billion simulations. I may well also have been using a memory-inefficient approach, though (if I held 5 numbers for each run, that would be 40GB of RAM I guess). My purpose behind this exercise is that I'm trying to demonstrate to a friend that you don't need to write custom C programs (which is what he did) to do this type of work, and that off the shelf (albeit specialised) languages can cope fine (where "fine" means "comparable to custom C"). So far, I'm finding that's not true - my experiments with various languages[1] have either been too slow or too memory hungry to make my case. When a tiny performance issue or over-use of memory in the implementation of the single experiment gets multiplied by factors on the order of millions or billions, that doesn't scale well enough. It's an interesting exercise that's got me learning a lot about various languages' strengths and weaknesses, though :-) Paul [1] Most of which have been at the "interested beginner" level, as here. ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
