Random number generator

ciccio

Hi,

Maybe slightly off topic here, but what algorithm is used for the
implementation of rand() in <cstdlib?

Or if it is not standardized (which it should), does anybody know what
it is in g++?

Thanks

Jun 27 '08 #1

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Ian Collins

ciccio wrote:

Hi,

Maybe slightly off topic here, but what algorithm is used for the
implementation of rand() in <cstdlib?

See section 7.20.2.2 of the standard for a portable implementation.

--
Ian Collins.

Jun 27 '08 #2

Ian Collins

Ian Collins wrote:

ciccio wrote:
>Hi,

Maybe slightly off topic here, but what algorithm is used for the
implementation of rand() in <cstdlib?

See section 7.20.2.2 of the standard for a portable implementation.

The C99 standard that is.

--
Ian Collins.

Jun 27 '08 #3

Kai-Uwe Bux

ciccio wrote:

Hi,

Maybe slightly off topic here, but what algorithm is used for the
implementation of rand() in <cstdlib?

Not specified by the standard.

Or if it is not standardized (which it should),

C++0X will have <randomwith standardized algorithms.

does anybody know what it is in g++?

http://sources.redhat.com/cgi-bin/cv...?cvsroot=glibc

You want to look at rand.c and random.c.
Best

Kai-Uwe Bux

Jun 27 '08 #4

James Kanze

On 15 avr, 10:57, Ian Collins <ian-n...@hotmail.comwrote:

ciccio wrote:

Maybe slightly off topic here, but what algorithm is used for the
implementation of rand() in <cstdlib?

See section 7.20.2.2 of the standard for a portable implementation.

That's the C standard, of course. And it's known to be a very
poor generator.

--
James Kanze (GABI Software) email:ja*********@gmail.com
Conseils en informatique orientée objet/
Beratung in objektorientierter Datenverarbeitung
9 place Sémard, 78210 St.-Cyr-l'École, France, +33 (0)1 30 23 00 34

Jun 27 '08 #5

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