Re: Simulation

• To: mathgroup at smc.vnet.net
• Subject: [mg19380] Re: [mg19353] Simulation
• From: "Andrzej Kozlowski" <andrzej at tuins.ac.jp>
• Date: Mon, 23 Aug 1999 13:57:04 -0400
• Sender: owner-wri-mathgroup at wolfram.com

```First, what is Table doing in

Table[NestList[#+0.01*Random[Integer,{-1,1}]&,5,1000]]

There are of course lots of ways to modify your code to do what you want.
Here is one that immediately comes to my mind:

p := Module[{v = Random[]}, Which[v < 1/6, 1, v < 5/6, 0, True, -1]]

data = NestList[# + 0.01*p &, 5, 20];

Slightly less obviously you can also use

p := Which[Random[] < 1/6, 1, Random[] < 1/5, -1, True, 0]

and lots of other ways.

--
Andrzej Kozlowski
Toyama International University
JAPAN
http://sigma.tuins.ac.jp
http://eri2.tuins.ac.jp

----------
>From: "Roberto Diego" <r-diego at develnet.es>
To: mathgroup at smc.vnet.net
>To: mathgroup at smc.vnet.net
>Subject: [mg19380] [mg19353] Simulation
>Date: Sat, Aug 21, 1999, 4:09 AM
>

> Hi there,
>
> I need help on how the expression:
>
> data=Table[NestList[#+0.01*Random[Integer,{-1,1}]&,5,1000]];
>
> could be modified in order to get -1 with probability 1/6, 0 with p 4/6 and
> 1 with p 1/6 instead of 1/3,1/3,1/3
>
> Thanks a lot
>
> Roberto Diego