Re: For Loop and Array related

*To*: mathgroup at smc.vnet.net*Subject*: [mg58002] Re: For Loop and Array related*From*: "Mariusz Jankowski" <mjankowski at usm.maine.edu>*Date*: Thu, 16 Jun 2005 05:36:00 -0400 (EDT)*Organization*: University of Southern Maine*References*: <d8oucl$t6q$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Strange indeed! However, the following gives a consistent total; in the body of the loop assign Random to a temporary variable n = Random[Integer,{1,100}]; Lattice[[n]]++ Also, the Do-loop construct is faster than For, ... and simpler, and if you need more speed use function Compile. Mariusz >>> mchangun at gmail.com<mchangun at gmail.com> 06/15/05 6:03 AM >>> Hi All, I have an array with 100 elements, all set to zero initially. Then I want to randomly choose one element and increase its value by one, and repeat this 16000 times. Here is my code: Lattice = Table[0, {n, 100}]; For[i = 1, i = 16000, i++, Lattice[[Random[Integer, {1, 100}]]]++] So now if I add all the elements in the list Lattice together, I should get 16000 (I use Total[Lattice] to get the sum of the list). But this doesn't happen, and strangely, each time I run this, the sum of the list is different! What am I doing wrong? Also I'm aware that a lot of Mathematica newbies try and write code like it were C++ and I think i've fallen into this trap as well. So is there a different (more Mathematica) way which I can implement the above? Thanks in advanced.