The Math Forum

Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Math Forum » Discussions » sci.math.* » sci.math

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: RNGs: A Super KISS
Replies: 14   Last Post: Feb 26, 2013 10:53 AM

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]

Posts: 21
Registered: 3/28/09
Re: RNGs: A Super KISS
Posted: Nov 3, 2009 3:32 PM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

On Nov 3, 10:46 am, geo <> wrote:
>   int refill( )
>   { int i; unsigned long long t;
>   for(i=0;i<41790;i++) { t=7010176LL*Q[i]+carry; carry=(t>>32); Q[i]=~
> (t);}
>   indx=1; return (Q[0]);
>   }

Not to nitpick but your C code could use some work. First off, some
indentation please? Second, returning a unsigned long long as "int"
is not very portable.

Part of the good thing of PRNGs is that they're reproduceable.
Ideally over different platforms. You should truncate the return
value if you want it as "int" or change the return type. As it stands
now this will produce different results on my x86-32 and 64 boxes for
the same seed, which is a bad thing.


Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© The Math Forum at NCTM 1994-2018. All Rights Reserved.