def test_bandpass(_data):
trace = _data['mseed'][0]
res = bandpass(trace, 2, 3)
assert not np.array_equal(trace.data, res.data)
assert trace.stats.starttime == res.stats.starttime
assert trace.stats.endtime == res.stats.endtime
assert trace.stats.npts == res.stats.npts
assert len(trace.data) == len(res.data)
def __bandpass_remresp(segment, config, trace, inventory):
"""Applies a pre-process on the given segment waveform by
filtering the signal and removing the instrumental response.
DOES modify the segment stream in-place (see below)
The filter algorithm has the following steps:
1. Sets the max frequency to 0.9 of the Nyquist frequency (sampling rate /2)
(slightly less than Nyquist seems to avoid artifacts)
2. Offset removal (subtract the mean from the signal)
3. Tapering
. Pad data with zeros at the END in order to accommodate the filter transient
nf['bandpass_freq_max']
5. Apply bandpass filter, where the lower frequency is set according to the magnitude
6. Remove padded elements
7. Remove the instrumental response
IMPORTANT NOTES:
- Being decorated with '@gui.preprocess', this function:
* returns the *base* stream used by all plots whenever the relative check-box is on
* must return either a Trace or Stream object
- In this implementation THIS FUNCTION DOES MODIFY `segment.stream()` IN-PLACE: from within
`main`, further calls to `segment.stream()` will return the stream returned by this function.
However, In any case, you can use `segment.stream().copy()` before this call to keep the
old "raw" stream
:return: a Trace object.
"""
# define some parameters:
evt = segment.event
conf = config['preprocess']
freq_max = conf['bandpass_freq_max']
if is_accelerometer(segment):
# accelerometer
freq_min = mag2freq(evt.magnitude)
else:
# velocimeter
freq_min = conf['velocimeter_freq_min']
# note: bandpass here below copied the trace! important!
trace = bandpass(trace,
freq_min=freq_min,
freq_max=freq_max,
max_nyquist_ratio=conf['bandpass_max_nyquist_ratio'],
corners=conf['bandpass_corners'],
copy=False)
trace.remove_response(inventory=inventory,
output=conf['remove_response_output'],
water_level=conf['remove_response_water_level'])
return trace
def bandpass_remresp(segment, config):
"""{{ PROCESS_PY_BANDPASSFUNC | indent }}
"""
stream = segment.stream()
assert1trace(stream) # raise and return if stream has more than one trace
trace = stream[0]
inventory = segment.inventory()
# define some parameters:
evt = segment.event
conf = config['preprocess']
# note: bandpass here below copied the trace! important!
trace = bandpass(trace,
mag2freq(evt.magnitude),
freq_max=conf['bandpass_freq_max'],
max_nyquist_ratio=conf['bandpass_max_nyquist_ratio'],
corners=conf['bandpass_corners'],
copy=False)
trace.remove_response(inventory=inventory,
output=conf['remove_response_output'],
water_level=conf['remove_response_water_level'])
return trace