The two dices

• To: mathgroup at smc.vnet.net
• Subject: [mg54486] The two dices
• From: "Antoine" <bugaboo12703 at yahoo.fr>
• Date: Mon, 21 Feb 2005 03:44:57 -0500 (EST)
• Sender: owner-wri-mathgroup at wolfram.com

```Hello,

I wanted to simulate the throws of two dices and something happened I can't
explain:
(Mathematica 5.0 , the same occurs on Mathematica 5.1 )

The following code is OK:

n=300;
theThrows = Table[Random[Integer, {1, 6}] + Random[Integer, {1, 6}], {n}];
theStats = Table[Count[theThrows, i], {i, 2, 12}]

the occurences, as n becomes greater and greater, looks like the Gaussian
curve
(sorry for my English)

Suppose you want your dice function, and that it is defined by

dice[]:=Random[Integer, {1, 6}]  ( nothing wrong about it, I suppose )

Now the behavior of the following code changes depending on the value of n.
If n < 250 everything is fine ...
hen n >= 250, then there is no occurence of odd values.
( the two dices never give 3, 5, ....)

n=250;
theThrows = Table[dice[] + dice[], {n}];
theStats = Table[Count[theThrows, i], {i, 2, 12}]

Does a rationnal explanation exists ?  Is it a bug ?

The two definitions ( see below ) of the dice function "makes" the code
running properly.
But, of course, I prefer the former definition.

dice:=Random[Integer, {1, 6}]  ( not so nice, specially if you want to have
several dice functions)
dice[_]:=Random[Integer, {1, 6}]   ( you must give a parameter to the
function, quite horrible )