Re: [ns] Generating random values having the probability density function

[Debojyoti Dutta <ddutta@ISI.EDU>]

You could also check the RNG object 

Debo

On Wed, 11 Oct 2000, Tarik Alj wrote:

> You could check the class RandomVariable to get an idea of how one can generate 
> random numbers. You could also look at traffic generators (expoo, pareto).
> 
> 
> >From: "Kejvan Redjamand (ERV)" <kejvan.redjamand@erv.ericsson.se>
> >To: ns-users@isi.edu
> >Subject: [ns] Generating random values having the probability density function
> >Date: Wed, 11 Oct 2000 16:08:14 +0200
> >MIME-Version: 1.0
> >
> >Hi
> >I'm a student doing my  Master Thesis. I need to implement a  function which
> >calculates (actually generates random value of I/S values given its
> >probability density function, f(x). How should the algorithm look like?
> >Can any one help me with checking my thoughts below?
> > I/S-values which is continuously distributed: f(x). It depends On N, number
> >of users in our system which can take discrete values. We must know the
> >typical values for I/S (we call it stochastic variable 'u'). 
> > f(x) means actually P(u=x), where x is an actual concrete value from the
> >values which the stochastic var u can take. 
> >Then by assuming N form MIN to MAX (e.g.-1000) we can calculate 
> >	1. probabilities f1, f2,... fmax and store them in an array: P.
> >	2. I/S values (i.e. concrete u's- u1..umax  corresponding to
> >probabilities) and store them in array U.
> >The first question is which u's can we take? (Note that u is takes continuos
> >values)
> >Then second question is that we need to use random I/S- values from (U), but
> >according to their probabilities from P; How can it be done?
> >The main question is: Is the whole idea reasonable?
> >
> >regards
> >
> >// Kejvan
> >Chalmers University of Technology, Sweden
> >	
> 
> Tarik Alj
> 
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