Re: Iterate through a list help

*To*: mathgroup at smc.vnet.net*Subject*: [mg77254] Re: Iterate through a list help*From*: dimitris <dimmechan at yahoo.com>*Date*: Wed, 6 Jun 2007 06:58:21 -0400 (EDT)*References*: <f43gfu$2cq$1@smc.vnet.net>

Again a recent thread begun by a similar question of you! I guess there were some confusion during the difficult work of the moderator or otherwise I don't understand what is happening! [Yes, it is possible that with so many posts that a message was duplicated. It is hard to remember something posted a few hundred mwssages ago. It am thinking about a way to avoid this - moderator] Dimitris / Nick : > Hello! I'm (somewhat) new to Mathematica and I need help to iterating > through a list and counting the occurrence of a number. > > My list looks like: > > {{1,0},{1,1},{2,x+x^2+x^4},{2,1+x+x^2+x^4},{4,x+x^2},{4,1+x+x^2},{4,x > +x^4},{4,1+x+x^4}, > {4,x^2+x^4},{4,1+x^2+x^4},{4,x^3+x^4},{4,1+x^3+x^4},{4,x+x^2+x^3+x^4}, > {4,1+x+x^2+x^3+x^4}, > {5,x+x^3},{5,1+x+x^3},{5,x^2+x^3},{5,1+x^2+x^3},{5,x+x^3+x^4},{5,1+x > +x^3+x^4},{5,x^2+x^3+x^4}, > {5,1+x^2+x^3+x^4},{8,x},{8,x^2},{8,x^3},{8,x^4},{8,1+x},{8,1+x^2}, > {8,1+x^3},{8,x+x^2+x^3},{8,1+x+x^2+x^3},{8,1+x^4}} > > The number that I would need to keep track of is the first in each > sub- > list. > > So for the first couple {{1,0},{1,1},{2,x+x^2+x^4},{2,1+x+x^2+x^4}, > {4,x > +x^2},........ > > I would need to keep track of 1,1,2,2,4........ > > It will not always be 1,2,4,5,8's. The numbers may be completely > different on each pass. Each sublist may be composed of more items > but the number that I need to keep track of will always be the 1st in > the sub-list. Any help or suggestions that you can give me will be > greatly appreciated. Thanks so much!