Introduction - If you have any usage issues, please Google them yourself
These codes will produce two ASCII output files:
btcs.out or ctcs.out. Lists delta_t, delta_x, and lambda. Also lists the final time requested vs. actual final time (these may differ if delta_t is not an even divisor of tfinal). Finally, lists the initial vs. final conditions at each point.
btcs.plt or btcs.plt. Approximate vs. real solution at each point.