confft

Introduction

This program calculates a fourier transform on its input data.
On stdin or as a commandline parameter (filename) it expects input-data consisting of one value per line.
Output is the real and imaginairy part of the transform.

Download

Download link:confft-0.4.tgz
This program requires FFTW (available as Debian package).


Example

I have a ... from which I retrieve measurement data with Open3600. All this data goes into a database. With the following script I retrieve all that data and draw a fourier transform of the outside-temperature:
#! /bin/sh

echo "SELECT temp_out FROM data ORDER BY timestamp" | /usr/bin/mysql -u fftread --password=fftread open3600 | tail -n +2 | confft -r | head -n 40 > /tmp/temp_out.dat

/usr/bin/gnuplot << EOF > /var/www/htdocs.keetweej.vanheusden.com/stats/temp_out-fft.png
set term png
set autoscale
set xlabel "freq"
set ylabel "amp."
plot "/tmp/temp_out.dat" with lines title "temperatuur"
EOF

rm -f /tmp/temp_out.dat
Result:






contact form Winnen in de Staatsloterij! disclaimer
Check out my united states Mega Millions lottery winning help page