Re: easy question about random numbers
- To: mathgroup at smc.vnet.net
- Subject: [mg53392] Re: [mg53382] easy question about random numbers
- From: Bob Hanlon <hanlonr at cox.net>
- Date: Sun, 9 Jan 2005 23:03:46 -0500 (EST)
- Reply-to: hanlonr at cox.net
- Sender: owner-wri-mathgroup at wolfram.com
li2={1/6,1/6,1/6,1/6,9/60,11/60};
li3=FoldList[Plus,0,li2];
drng[] := Module[{x=Random[]},Count[li3,_?(#<x&)]];
data=Table[drng[],{10000}];
(Count[data,#]&/@Range[6])/Length[data]//N
{0.1609,0.1703,0.1653,0.1659,0.1511,0.1865}
(Plus@@%)==1
True
Round[60*#]/60&/@%%
{1/6, 1/6, 1/6, 1/6, 3/20, 11/60}
Bob Hanlon
>
> From: Pedrito <pedrito6 at softhome.net>
To: mathgroup at smc.vnet.net
> Date: 2005/01/08 Sat PM 11:02:44 EST
> To: mathgroup at smc.vnet.net
> Subject: [mg53392] [mg53382] easy question about random numbers
>
> Hi everybody!
>
> I wanted to obtain a discrete random number generator that I needed for
> a project.
>
> On the library Statistics`DiscreteDistributions` I could find the
DiscreteUniformDistribution
> function. But I wanted to specify the probability for each one of the
> states.
>
>
> For instance:
> If we need to simulate an unfair dice, we could have this probabilities
> for each one of the sides:
> {1/6, 1/6, 1/6, 1/6, 9/60, 11/60}
>
> So I wrote:
> li2 = {1/6, 1/6, 1/6, 1/6, 9/60, 11/60}
> li3=FoldList[Plus,0,li2]
> Module[{i = 1, r = Random[]}, While[ !li3[[i]] < r < li3[[i + 1]], i++]; i]
>
> It works ok but I don't know if there is another (better) way of doing
> this.
> Any suggestion?
>
>