[Mono-osx] bug in Random
Duane Wandless
duane at wandless.net
Sun Jan 25 15:17:15 EST 2009
>
> Rodrigo is on the Mono team and has already answered you.
Not very obvious he (kumpera at gmail.com) is on the Mono team... actually it
just seemed like the response was from a random mono user. Ha! Joke aside,
that is what I thought.
Anyway... for what it is worth, I disagree. The advantage of having the
same pseudo random numbers given the same seed is important. Yes I can
write my own algorithm to accomplish that but I prefer not to reinvent the
wheel. That was and most of the time is one of the biggest advantages of
Mono. I do not have to rewrite code... I can reuse from Windows to Mac to
Linux and I can focus on the core functionality of my applications. Not
random differences between the OSes or random programming languages specific
to that OS.
My only request is that the decision not to provide the same functionality
as the Microsoft's library in this case was indeed by design and not a
random decision by some random developer.
Okay -- enough random jokes... but the request is legit.
Thanks for the responses.
Duane
On Sun, Jan 25, 2009 at 2:30 PM, Geoff Norton <gnorton at novell.com> wrote:
> Rodrigo is on the Mono team and has already answered you.
>
> On Sun, 2009-01-25 at 14:24 -0500, Duane Wandless wrote:
> > Hello Mono-team... Can you please provide an answer? Was the
> > intention to use a different algorithm for the Random class, or was
> > that a mistake? Honestly I cannot see a technical reason to use a
> > different one.
> >
> >
> > Thanks.
> >
> > On Mon, Jan 19, 2009 at 5:43 PM, Rodrigo Kumpera <kumpera at gmail.com>
> > wrote:
> > 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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> > >> http://lists.ximian.com/mailman/listinfo/mono-osx
> > >>
> > >>
> > >
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> > >
> > >
> >
> >
> > --
> > View this message in context:
> >
> http://www.nabble.com/bug-in-Random-tp21544091p21553211.html
> > Sent from the Mono - OSX mailing list archive at
> > Nabble.com.
> >
> >
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