I do most of my computational astrophysics work in Mathematica. The program is incredibly powerful, but you have to be very specific in how you tell it what to do. If you slip up, Mathematica will try its best to follow your incorrect instructions. Case in point, a while back I needed to plot a Hertzsprung-Russell diagram for the book. The conversation went basically like this:
Me: Mathematica, I want you to plot this data table of 50,000 stars, absolute magnitude vs color.
Mathematica: Consider it done, Boss.
Me: And Mathematica, I want you to make each point tiny.
Mathematica: Umm…okay…I’m on it, Boss.
It did exactly what I asked…