Help on iteration

*To*: mathgroup at smc.vnet.net*Subject*: [mg54942] Help on iteration*From*: Clifford Martin <camartin at snet.net>*Date*: Mon, 7 Mar 2005 02:10:26 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

I've got a simple problem I can't seem to get right. Here is a sample set of data glist={{a,b,c,d,e,f,g,h,l,m,n,o,p,q,Date1}, {a,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,Date2}, {a,R,s,t,u,v,X,Y,z,aa,bbb,cc,dd,tt,Date3}}; What I want to do is look at the 14th element in each sublist. (For example in the above example data that would be values q, Q and tt). If any value is equal to zero (in my example lets say that tt =0) I want to 1.Check the date. 2.Pull a value associated with that date ,lets call it zzz. (that I've entered somewhere else and made a variable). 3. Calculate a new value for tt (non zero) using a calculation such as (s-C)+zzz. 4. Replace the value of tt(that was zero) with the new calculated value. 5. I want to do this for every list in my data set. My actual case is a bit more complicated than this but if I can see how to do something like this I can probably figure out my problem. Thanks for any help. Cliff

**Follow-Ups**:**Re: Help on iteration***From:*Chris Chiasson <chris.chiasson@gmail.com>