Re: dft : property of symmetry for real & even seq

On 8 Mar, 17:53, "Steven G. Johnson" <stev...@xxxxxxxxxxxx> wrote:

 The FFT function in
Matlab is O(N log N) for all N, even for prime N (although prime N are
a few times slower than highly composite N).

Just out of curiosity, how does this order reduction work for prime N?
I would assume off the top of my head that the FFT only speeds things
up for composite N?

Rune
.