fft issues



dlakelan wrote:
> I am trying to use the maxima fft routines to do some numerical 
> solutions of PDEs that I derived using maxima. I want to discretize the 
> space, and then use the fft to calculate derivatives and second 
> derivatives etc in space.
> 
> There are some irregularities that I'm experiencing in the whole process.

Duh. the thing about the fourier transform is you always have to be 
careful about how you define frequency... some people use omega in 
radians and some people use f in cycles, and you can easily confuse 
yourself... I think I was doing that. so ignore this message for now.