Filtering frequency-domain data

Frequency-domain data (a FrequencySeries or a Spectrogram) can be filtered using an arbitrary filter using the filter() methods of those objects:

FrequencySeries.filter(filt, *[, analog, ...])

Apply a filter to this FrequencySeries.

Spectrogram.filter(filt, *[, analog, ...])

Apply the given filter to this Spectrogram.