SUFFT - fft real time traces to complex frequency traces

suftt <stdin >sdout sign=1

Required parameters:
none

Optional parameters:
sign=1 sign in exponent of fft
dt=from header sampling interval
verbose=1 =0 to stop advisory messages

Notes: To facilitate further processing, the sampling interval
in frequency and first frequency (0) are set in the
output header.

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

Caveats:
No check is made that the data IS real time traces!

Output is type complex. To view amplitude, phase or real, imaginary
parts, use suamp

Examples:
sufft < stdin | suamp mode=amp | ....
sufft < stdin | suamp mode=phase | ....
sufft < stdin | suamp mode=real | ....
sufft < stdin | suamp mode=imag | ....


Credits:

CWP: Shuki Ronen, Chris Liner, Jack K. Cohen

Note: leave dt set for later inversion

Trace header fields accessed: ns, dt
Trace header fields modified: ns, d1, f1, trid