A TruBasic program for doing the iteration of a linear function is available on the computers in Clapp 420 under (click on "My Computer") C:/Program_Files/math/math251/Chap1.
An equivalent Matlab program is available here. To run it, you would have to copy this script into a text file with the extension .m, then open Matlab (a computational package available on Math Department machines), and run the script from the Matlab command window. All easier than it sounds! We'll see how to do such things in class.