Funny plots in MATLAB: what does lower scale mean?

I recently learned the ezplot function in MATLAB. Recently I typed in

ezplot('x^y - y^x', [-100 100 -100 100]);

and this is what I got;

alt text http://www.freeimag开发者_开发技巧ehosting.net/uploads/0df94f44aa.png

Can anyone please tell me whatever is happening ? for lower scaling of x and y ( [ -10 10 -10 10]) there are more patterns in the 2nd 3rd and 4th quadrants.

I was not very sure of the shape of curve, but I did not expect this !

I think that all bets are off when you ask Matlab to plot a function of 2 variables in only 2 dimensions. Especially so when some of the values occurring in your function are 1/0.

What is happening is that you are exposing the limitations of general purpose graph drawing tools to deal with functions for which they are not designed, and reminding yourself that you need some understanding yourself of what the computer is doing to be sure that the output you get is meaningful.

What shape did you expect the graph to be ?