.TH FFTANAL 1carl CARL
.SH NAME
fftanal \- analyze power spectrum of fft for peaks
.SH SYNOPSIS
.B fftanal 
[
.B flags
] 
< fft_power_spectrum > output
.sp
Input must be a file or pipe of floatsams.
Output is [frequency, amplitude] pairs, arabic if standard output is
a terminal, floatsams otherwise.
.SH FLAGS
.TP
.B -nN
number of expected nodes (1024)
.TP
.B -wN
window size used by the fft (16K)
.TP
.B -RN
sample rate of original sample data (DHISR)
.TP
.B -tN
minimum amplitude threshold (.0001)
.PP
.SH DESCRIPTION
.B fftanal
reads the power spectrum on its standard input (from, for example, 
.I spect(1carl))
and walks it through looking for peaks which exceed the threshold.
It produces a data-reduced
stream of numbers of the [x,y] values
of the peaks.  The threshold may be specified with the
"dB" postoperator.
For terminal output, amplitude is in dB of intensity.
.PP
.SH AUTHOR
Gareth Loy
.SH SEE ALSO
spect(1carl), harmanal(1carl).
