[Mono-osx] bug in Random
Geoff Norton
gnorton at novell.com
Sun Jan 25 15:26:40 EST 2009
Duane,
Is there some reason juts copying our Random class into your library
doesn't work for you? Its MIT/X11 licensed so you have no concerns if
your project is commercial, and you'll get the same results on all CLRs
then.
-g
On Sun, 2009-01-25 at 15:17 -0500, Duane Wandless wrote:
> 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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> > >>
> > >>
> > >
> > >
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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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