The long march through Computing methods:Runge methods

The graph above (which I made using Octave) shows the Runge phenonmenon in polynomial intepolation,


This term I chose an interesting cource called Computing method,
someone think it dull,but I am interested in it very much.
Only by that can I realize the power of Computing.
By the way Matlab is a great tool.
However I've not enough money to pay for it,so I decided to use Octave(a free numerical computing program)instead,that is good too!