SUIFFT - fft complex frequency traces to real time traces

suiftt <stdin >sdout sign=-1

Required parameters:
none

Optional parameter:
sign=-1 sign in exponent of inverse fft

Output traces are normalized by 1/N where N is the fft size.

Note: sufft | suifft is not quite a no-op since the trace
length will usually be longer due to fft padding.


Credits:

CWP: Shuki, Chris, Jack

Trace header fields accessed: ns, trid
Trace header fields modified: ns, trid