obspy.core.trace.Trace.filter

Trace.filter(type, *args, **options)

Filter the data of the current trace.

Parameters:

• type (str) – String that specifies which filter is applied (e.g. "bandpass"). See the Supported Filter section below for further details.

• args – Only filter frequency/frequencies can be specified as argument(s). Alternatively filter frequencies can be specified as keyword arguments.

• options – Keyword arguments for the respective filter that will be passed on. (e.g. freqmin=1.0, freqmax=20.0 for "bandpass")

Note

This operation is performed in place on the actual data arrays. The raw data is not accessible anymore afterwards. To keep your original data, use copy() to create a copy of your trace object. This also makes an entry with information on the applied processing in stats.processing of this trace.

Supported Filter

'bandpass'

Butterworth-Bandpass (uses obspy.signal.filter.bandpass()).

'bandstop'

Butterworth-Bandstop (uses obspy.signal.filter.bandstop()).

'lowpass'

Butterworth-Lowpass (uses obspy.signal.filter.lowpass()).

'highpass'

Butterworth-Highpass (uses obspy.signal.filter.highpass()).

'lowpass_cheby_2'

Cheby2-Lowpass (uses obspy.signal.filter.lowpass_cheby_2()).

'lowpass_fir' (experimental)

FIR-Lowpass (uses obspy.signal.filter.lowpass_fir()).

'remez_fir' (experimental)

Minimax optimal bandpass using Remez algorithm (uses obspy.signal.filter.remez_fir()).

Example

>>> from obspy import read
>>> st = read()
>>> tr = st[0]
>>> tr.filter("highpass", freq=1.0)  
<...Trace object at 0x...>
>>> tr2 = st[1]
>>> tr2.filter("lowpass", 1.0)  
<...Trace object at 0x...>
>>> tr.plot()  

(Source code, png)