Re: Portable random number generator

"osmium" <>
Wed, 10 Nov 2010 09:11:23 -0600
"Victor Bazarov" wrote:

On 11/9/2010 11:12 PM, Gus Gassmann wrote:

I am collaborating on a rather large project with complicated XML
files (some objects nest ten levels deep) and corresponding data
handling challenges. I want to do proper testing of the (C++) code and
decided that the only way to go is random tests. So now I am looking
for a random number generator with the following properties:

1. Portability.
2. Random starting points.
3. Replicability on demand.

I presume this means that I would seed the RNG based on the clock, but
keep a copy of the seed that I could optionally use at the start in
case I found a problem on a previous run.

Statistical properties are of lesser importance.

I presume I am not the first person to attempt this and am hoping to
find some guidance here. Both C and C++ would be OK for the RNG, hence
the cross-post.

Thanks for any hints.

I am afraid to ask... Why not use 'srand/rand' pair of functions? You
can always do

     unsigned seed = (unsigned)time(0); // for keeping

Of course, it's so damn obvious that I expect some kind of a trick...

I assume by portable he means the same sequence would be provided from a
given seed regardless of the target computer.

rand() gets an F on that.

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