obspy.signal.filter.lowpass

lowpass(data, freq, df, corners=4, zerophase=False)[source]

Butterworth-Lowpass Filter.

Filter data removing data over certain frequency freq using corners corners. The filter uses scipy.signal.iirfilter() (for design) and scipy.signal.sosfilt() (for applying the filter).

Parameters:

  • data (numpy.ndarray) – Data to filter.

  • freq – Filter corner frequency.

  • df – Sampling rate in Hz.

  • corners – Filter corners / order.

  • zerophase – If True, apply filter once forwards and once backwards. This results in twice the number of corners but zero phase shift in the resulting filtered trace.

Returns:

Filtered data.