Is there a way to draw an initial signal and then take the value of the signal as input at some discrete points for further calculations?

I'm writing a program to solve inviscid Burger's equation which requires an initial condition. I would like to draw some random curve and take it as input at discrete points rather than writing the initial condition in my code.

[Jan]

Answering would be easier if you post more details, e.g. the relevant part of the code.