davide lasagna wrote: > Hello everybody, > this is my first post in this list. > > I'm plotting a spectrogram with > > Pxx, freqs, bins, im = specgram(y, nfft=256, f_sampling=12000) > > and i want to add a colorbar with > > colorbar() > > > The problem is that the color scale seems to be wrong with respect to > the data in Pxx, i.e. Pxx is of the order of 1e-2 while in the colorbar > i have tick values spanning from -20 to -180. What is the problem??
specgram and psd plot power in decibels: 10*log10(Pxx). Because they involve heavy computation and application-specific choices, like the decibel scale, they really should not be axes methods. You can make a function plot the spectrogram however you like by looking at the source code in the Axes.specgram method (the pyplot specgram function is just a thin wrapper for this method), which is using mlab.specgram to do the calculation and is then just scaling and plotting. Eric > > Thanks in advance! > > > Davide > > > ------------------------------------------------------------------------------ > Enter the BlackBerry Developer Challenge > This is your chance to win up to $100,000 in prizes! For a limited time, > vendors submitting new applications to BlackBerry App World(TM) will have > the opportunity to enter the BlackBerry Developer Challenge. See full prize > details at: http://p.sf.net/sfu/Challenge > _______________________________________________ > Matplotlib-users mailing list > Matplotlib-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/matplotlib-users ------------------------------------------------------------------------------ _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
