Replacing a part of a list/matrix?

*To*: mathgroup at smc.vnet.net*Subject*: [mg2180] Replacing a part of a list/matrix?*From*: olee at ripco.com (O. Lee)*Date*: Thu, 12 Oct 1995 01:59:16 -0400*Organization*: Ripco BBS, Free Trial account (312) 665-0065

I am trying to assign a value to a matrix position, such as: pop[[ x,y ]] = value in a module function. When I try manually assigning a value to the matrix position outside of the module, it works. When I run the function with the statement, Mathematica gives me the following error message: Part::setps: {{1, 1, 0, 0}, <<1>>} in assignment of part is not a symbol. Can anyone tell me how to get the assignment statement to work! I isolated the problem in the function to this line and I am sure that what I just described was the problem. I have tried using the command: pop=ReplacePart[pop,value,{x,y}] but it gives me even more error messages! Help me please! I appreciate any help. Thanks. O. Lee