On Friday, 20 July 2012 at 09:47:52 UTC, Andrea Fontana wrote:
I read that default RNG in phobos is Mersenne Twister.
I think it would be a good idea to replace it with
complementary-multiply-with-carry (cmwc). CMWC is faster (use
simpler
math), has a longer period (standard implementation has a
2^131104
period vs 2^19937 of current MT implementation in phobos) and
passed
diehard tests (mt passes them too)
And of course it's very easy to implement:
http://en.wikipedia.org/wiki/Multiply-with-carry#Implementation
I'd say the problem is that it is not a very widespread or known
PRNG.
While I wouldn't be against adding it to the library ("I see no
reason not to add it"), making it the _default_ PRNG is a whole
other story.
Users that choose "default" want something reliable, documented,
trustworthy etc...
Multiply With Carry seems like it is Cutting Edge to me, not yet
widespread, known or tested. I'd say it should only be used by
those that explicitly request it's usage.
