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Subject: Re: Correlated random numbers ...
From: Christophe Le Page (lepage@cirad.fr)
Date: lun nov 26 2001 - 18:50:55 CET
Hummmmm... For that kind of very sharp question, not so specific
to Cormas, you could try the wider channel vwnc@cs.uiuc.edu.
This is the forum for the VisualWorks NC community. For subscribing
and unsubscribing from vwnc, write at vwnc-request@cs.uiuc.edu
(and not to vwnc@cs.uiuc.edu ) with Subject as "subscribe" or
"unsubscribe".
I guess the probability to reach someone able to help you should
increase... Let me test this feeling: I send the question for you to vwnc
and I will report here the result...
clp
----- Original Message -----
From: Jourdain, Damien <D.JOURDAIN@CGIAR.ORG>
To: <cormas@cnusc.fr>
Sent: Monday, November 26, 2001 6:08 PM
Subject: Correlated random numbers ...
> Thank you Pierre and Louise for the prompt answer on Random numbers. It is
> working now.
>
> I have another question related to random numbers and somehow tougher!
>
> How can I do if I want to generate two (or more) series of random numbers
> that are correlated.
>
> For example, I want to generate a first serie of number following the normal
> distribution N(1500, 100), and a second serie of number following also a
> normal distribution N(2000, 300), and I want a coefficient of correlation
> between the two series of let say 0.8?
>
> Any simple solution?
>
>
>
> Damien
>
> -----Original Message-----
> From: Pierre Bommel [mailto:bommel@cirad.fr]
> Sent: Monday, November 26, 2001 9:55 AM
> To: Jourdain, Damien
> Cc: cormas@cnusc.fr
> Subject: Re: Random numbers ...
>
>
> Hello Damien,
>
> Jourdain, Damien wrote:
>
> > Dear all,
> >
> > I try to generate a serie of random numbers uniformely distributed between
> > let say 0.7 and 0.1. I thought the routine to use would look something
> like
> >
> > | x y |
> > x := OrderedCollection new.
> > 1 to: 100 do: [ :p |
> > y := Cormas randomFrom: 0.7 to: 1.
> > x add: y.
> > ].
> >
> > This, in fact generate a serie of numbers that are either 0.7 or 1 but
> > nothing in between.
> > What did I do wrong?
> >
> The class method "randomFrom:to:" return an integer (if the start value
> is an integer), for example: Cormas randomFrom: 7 to: 10 can only return
> 4 values = 7, 8, 9 or 10.
> In your case, if you want a collection of floats, between 0.7 and 1 with
> a precision of 3, you can do that by this way :
>
>
> | x y |
> x := OrderedCollection new.
> 1 to: 100 do: [ :p |
> y := (Cormas randomFrom: 700 to: 1000)/1000 asFloat.
> x add: y].
>
> Best regards,
>
> Pierre
>
> --
> **************************************
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> * 34398 Montpellier cedex 5 France *
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