[SciPy-User] butter() and filtfilt() - differences between MATLAB and scipy

Fabrice Silva silva@lma.cnrs-mrs...
Fri Jun 28 08:00:44 CDT 2013

Tristan Strange a écrit :
> > You should maybe worry about getting (in matlab) such values for b. All
> > are pretty close to 0. This is what scipy implementation is warning you
> > about ("Badly conditioned filter coefficients (numerator): the results
> > may be meaningless"). Using this b vector may lead to output signals
> > prone to numerical noise...
> Ok, thanks. Apparently the MATLAB implementation functions as expected....

Does it mean that you checked the frequency response of the filter ?
(with scipy.signal.freqz and matlab's freqz)

More information about the SciPy-User mailing list