Structure modification and related questions

*To*: mathgroup at smc.vnet.net*Subject*: [mg13857] Structure modification and related questions*From*: "Roberto Moriyon" <Roberto.Moriyon at ii.uam.es>*Date*: Wed, 2 Sep 1998 01:30:54 -0400*Organization*: Universidad Autonoma de Madrid, Spain*Sender*: owner-wri-mathgroup at wolfram.com

Hello, I am working with a big structure (actually, it is a list), like x=Table[i, {i,10000}] Q.1) Can I modify x[[3]], let's say, without having to create another list of 10000 elements? (the obvious thing for me to try, x[[3]]=0, does not work). Q.2) In the same spirit, are there any functions similar to Insert and Delete, that modify directely the expression affected by them, without taking a whole copy? Q.3) Related to Q.1&2, is it possible in Mathematica that two structures (or lists, for that sake) have some parts in common? What I mean by this is that, for example, I would like to have the variable x equal to the second element of {1,{2,3},4}, so that in case the 3 is changed by a 5 in one of them, it is also changed in the other one. Thank you for any help you can give me on this Roberto Moriyon -- Roberto Moriyon Departamento de Ingenieria Informatica Universidad Autonoma de Madrid 28049 Madrid Phone: +34-91-397-4350 Fax: +34-91-397-5277