Improving pseudo-highpass filtering

(only used in post-precessing for determining max. amplitudes)

TM/waveformops.py

@@ -532,22 +532,33 @@ def _waveform_processing_trace(trace, resampling, procType='bandpass', freqMax=N
 
     # We filter first, and then re/downsample;
     # This costs more performance (more to filter), but the data will be represented "better"
-        trace.filter("bandpass", freqmin=config.filtConf[0],
-                     freqmax=config.filtConf[1], corners=config.filtConf[2])
     if procType == 'bandpass' and config.FFT_filt is False:
 
+        corners = config.filtConf[2]
+        zerophase = False
+        if zerophase:
+            corners = corners//2
+
+        trace.filter("bandpass", freqmin=config.filtConf[0], freqmax=config.filtConf[1],
+                     corners=corners, zerophase=zerophase)
+
     elif procType == 'highpass':
-        trace.filter("highpass", freq=1.0)
-        # If maximum freq specified, apply also a low-pass filter
-        #   (to remove too-high frequencies that disturb the amplitude comparison)
-        if freqMax:
+
+        if not freqMax:
+
+            trace.filter("highpass", freq=1.0)  # 4th order
+
+        else:
+            # If maximum freq specified, apply a bandpass filter
+            #   (to remove too-high frequencies that disturb the amplitude comparison)
+
             # Determine lowest senseful frequency
             # (at max, only up to Nyquist of original signal, or
             #  if signal will be resampled below/equal Nyquist freq, take the new sampling rate)
             freqmax = min(resampling if resampling else float('Inf'),   # New sampling freq
-                          trace.stats.sampling_rate//2,          # Nyguist freq
+                          trace.stats.sampling_rate//2,                 # Nyguist freq
                           freqMax)                                      # Specified max. freq
-            trace.filter("lowpass", freq=freqmax)
+            trace.filter("bandpass", freqmin=1.0, freqmax=freqmax)  # 4th order
 
     # Apply 50Hz bandSTOP filter if configured
     if config.stop50Hz and config.FFT_filt is False: