quick bug?

Hi, just thought I'd check if this was a (fairly minor) bug. In the psd function there is:

    if NFFT % 2:
        raise ValueError, 'NFFT must be a power of 2'

But that will only check if NFFT is an even number or not. Should this instead be:

    if not ispower2(NFFT):
       raise ValueError, 'NFFT must be a power of 2'

?

Abe