[EMAIL PROTECTED] wrote: > Hello, > > I am ploting a fft periodogram of my data using a script (found in > internet: http://linuxgazette.net/115/andreasen.html ) that gave me > good results before. There should be a periodicity of >160 in the data > as can be seen by eye. However, this script now says that there is > periodicity of ~9. Can somebody explain me what's wrong? Thank you in > advance.
The units are wrong on your period axis. Right now you have them in units of "sample-spacing". So, the plot is telling you that you have a periodicity of ~9 sample spacings. To get it in unites of minutes you need to multiply period by the difference in minutes period_in_minutes = period * (minutes[1] - minutes[0]) Then, plot period_in_minutes versus power. I see a peak around 180 minutes in your data. -Travis -- http://mail.python.org/mailman/listinfo/python-list
