Re: parallel

Here is an exercise .. a homework assignment .. to enhance 
understanding of the algorithms.

Consider the well known Fast Fourier Transform.  Compare it to a 
plain (non-fast) discrete Fourier Transform that takes the same 
data and computes the same result.

What is it that makes the "Fast" Fourier Transform fast?  How 
was it derived?  What is the principle behind it?  How much 
faster is it?

How does that concept relate to the matrix ordering being 
discussed here?

Where else might this concept be used to make it faster?