Le lundi 30 janvier 2012 à 11:45 +0000, David Craig a écrit : > Hi I have some data for a 24hr period with a sample rate of 100 > samples/second. I want to create a power spectrum using matplotlibs > function psd. I want it to have 10 minute windows with a 50% overlap, > but cant seem to get the syntax right. My code is as follows: > > NFFT = len(data) > Fs = 100 > window=np.hanning(Fs*60*10) > noverlap = window*0.5 > plt.psd(data, NFFT, Fs, window, noverlap ) > > anyone kow how to do this properly???
Be careful to use a suitable value for NFFT. It must be linked to your windows size, not the total data length, and you would rather use a power of 2 for efficience. Do not use it to increase the frequency resolution (use pad_to instead). Fs = 100 NFFT = Fs*60*10 Pxx, f = plt.psd(data, NFFT, Fs, window=np.hanning(NFFT), NFFT/2) -- Fabrice Silva ------------------------------------------------------------------------------ Try before you buy = See our experts in action! The most comprehensive online learning library for Microsoft developers is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, Metro Style Apps, more. Free future releases when you subscribe now! http://p.sf.net/sfu/learndevnow-dev2 _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
