Do you have access to MATLAB?

The MathWorks - MATLAB and Simulink for Technical Computing

There are many packages out there that will help you do, I recommend MATLAB as thats what I am familiar with and I have used it for a similar thing when I modeled the motion of a surge wave. Octave is a free alternative that I assume would also be well suited (although it is my opinion that MATLAB has better graphics).

Regards Elbarto