I currently don't know how to use any such programs like this. I took a C++ class along time ago but barely remember it. I am a junior undergrad and feel like it is very important that I learn to use some such program like one of these. Does anyone have any suggestions on what would be the best program to learn might be, the best method, the best book or website or anything that could help me learn this stuff on my own? How important is this sort of stuff for a physicist? I know it's a stupid question but I figured I'd ask anyways.