[Mono-osx] bug in Random

[Rodrigo Kumpera]

Your application depends on an implementation detail of the MS runtime.
There is no guarantee either that they won't change the Random algorithm.

This is unfortunate to your application but the solution is pretty simple,
copy mono's
implementation to your project and rely on it instead of an external prng.


On Mon, Jan 19, 2009 at 8:38 PM, MacUser <atlas at spiralgraphics.biz> wrote:

>
> This is also a point of concern for me.  My code , written on Microsoft
> .NET,
> relied on the fact that using the same seed will always produce the same
> series of numbers.  To port to Mono, not only would I need Mono's Random()
> to be consistant across all Mono platforms, but also consistant to the
> results that Microsoft's Random() produces.
>
> By the way, I work in the algorithmic graphics generation area, where an
> image produced with the same input values must always look the same
> regardless of the platform the app is running on.  This is why reliable
> seeding is so important.
>
>
>
> Rodrigo Kumpera wrote:
> >
> > It doesn't state the the algorithm has to be the same, just that it must
> > be
> > reproducible given the same seed.
> >
> > On Mon, Jan 19, 2009 at 3:27 PM, Duane Wandless <duane at wandless.net>
> > wrote:
> >
> >> That is a valid question.  From MSDN, the Random class is a
> Pseudo-random
> >> number generator:
> >> The random number generation starts from a seed value. If the same seed
> >> is
> >> used repeatedly, the same series of numbers is generated.
> >>
> >> http://msdn.microsoft.com/en-us/library/system.random.aspx
> >>
> >> The value in this is that given a seed will produce the same sequence of
> >> random numbers.  So if the client and server both know the seed then
> >> the algorithm will work correctly on both platforms.
> >>
> >>
> >> On Mon, Jan 19, 2009 at 12:09 PM, Matt Emson
> >> <memsom at interalpha.co.uk>wrote:
> >>
> >>> Duane Wandless wrote:
> >>>
> >>>> Maybe I incorrectly assume that the pseudo-random number should be the
> >>>> same on both platforms... but I believe that it should be a
> predictable
> >>>> sequence given the same seed.
> >>>>
> >>> Maybe this is a silly question, but why would you want your *random*
> >>> number to be the same on both platforms, more so "a predictable
> >>> sequence"?
> >>> Sure I'm missing something obvious, but... ?!
> >>>
> >>
> >>
> >> _______________________________________________
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> >>
> >>
> >
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> >
> >
>
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>
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