random() ?

try here

http://www.math.keio.ac.jp/~matumoto/emt.html

and look for the ''c codes'' section.

I don''t understand why everyone doesn''t use this generator - it produces a range of 2^32-1 random numbers, over a much longer period than the built in rand() ... and if that isn''t good enough ... it''s actually faster too

Regards

quote:

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Original post by Shag
try here

http://www.math.keio.ac.jp/~matumoto/emt.html

and look for the ''c codes'' section.

I don''t understand why everyone doesn''t use this generator - it produces a range of 2^32-1 random numbers, over a much longer period than the built in rand() ... and if that isn''t good enough ... it''s actually faster too

Regards

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am i wrong or using a srand will create larger than that ?
srand ((unsigned) time (NULL)) ?

No - the rand function only returns a number between 0-2^15

Look for the MAX_RAND (i think) definition


[edited by - Shag on February 20, 2003 7:50:29 AM]

is that a Japanese site you gave me ? My browser doesn''t support japanese and it wouldn''t make much difference even if it did. So, why dont you simply tell me the basic theory behind it

Believe me, my japanese isn''t as good as it could be - the site is in english!

However, there is a dialog that pops up about installing some foreign font - i just ignore it and everything is fine

OOPS

I never actually told you what the site was about!

There is a random number generator called a Mersenne Twister. This is what i was pointing you too!

Do a search in google

Here''s one you might try:

unsigned long Rand(unsigned long* seedP) {
	unsigned long	seed = *seedP;
	unsigned long	rval = 0;
	__asm {
		mov		eax,343FDh;
		imul	        seed;
		add		eax,269EC3h;
		mov		seed,eax;
		ror		eax,8;
		mov		rval,eax;
	}
	*seedP = seed;
	return rval;
}
 

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