diff options
Diffstat (limited to 'gr-filter/python/optfir.py')
| -rw-r--r-- | gr-filter/python/optfir.py | 117 |
1 files changed, 68 insertions, 49 deletions
diff --git a/gr-filter/python/optfir.py b/gr-filter/python/optfir.py index bccb8c68d0..47b0ac4e8d 100644 --- a/gr-filter/python/optfir.py +++ b/gr-filter/python/optfir.py @@ -32,16 +32,20 @@ import filter_swig as filter # ---------------------------------------------------------------- -## Builds a low pass filter. -# @param gain Filter gain in the passband (linear) -# @param Fs Sampling rate (sps) -# @param freq1 End of pass band (in Hz) -# @param freq2 Start of stop band (in Hz) -# @param passband_ripple_db Pass band ripple in dB (should be small, < 1) -# @param stopband_atten_db Stop band attenuation in dB (should be large, >= 60) -# @param nextra_taps Extra taps to use in the filter (default=2) def low_pass (gain, Fs, freq1, freq2, passband_ripple_db, stopband_atten_db, nextra_taps=2): + """ + Builds a low pass filter. + + Args: + gain: Filter gain in the passband (linear) + Fs: Sampling rate (sps) + freq1: End of pass band (in Hz) + freq2: Start of stop band (in Hz) + passband_ripple_db: Pass band ripple in dB (should be small, < 1) + stopband_atten_db: Stop band attenuation in dB (should be large, >= 60) + nextra_taps: Extra taps to use in the filter (default=2) + """ passband_dev = passband_ripple_to_dev (passband_ripple_db) stopband_dev = stopband_atten_to_dev (stopband_atten_db) desired_ampls = (gain, 0) @@ -51,19 +55,23 @@ def low_pass (gain, Fs, freq1, freq2, passband_ripple_db, stopband_atten_db, taps = filter.pm_remez (n + nextra_taps, fo, ao, w, "bandpass") return taps -## Builds a band pass filter. -# @param gain Filter gain in the passband (linear) -# @param Fs Sampling rate (sps) -# @param freq_sb1 End of stop band (in Hz) -# @param freq_pb1 Start of pass band (in Hz) -# @param freq_pb2 End of pass band (in Hz) -# @param freq_sb2 Start of stop band (in Hz) -# @param passband_ripple_db Pass band ripple in dB (should be small, < 1) -# @param stopband_atten_db Stop band attenuation in dB (should be large, >= 60) -# @param nextra_taps Extra taps to use in the filter (default=2) def band_pass (gain, Fs, freq_sb1, freq_pb1, freq_pb2, freq_sb2, passband_ripple_db, stopband_atten_db, nextra_taps=2): + """ + Builds a band pass filter. + + Args: + gain: Filter gain in the passband (linear) + Fs: Sampling rate (sps) + freq_sb1: End of stop band (in Hz) + freq_pb1: Start of pass band (in Hz) + freq_pb2: End of pass band (in Hz) + freq_sb2: Start of stop band (in Hz) + passband_ripple_db: Pass band ripple in dB (should be small, < 1) + stopband_atten_db: Stop band attenuation in dB (should be large, >= 60) + nextra_taps: Extra taps to use in the filter (default=2) + """ passband_dev = passband_ripple_to_dev (passband_ripple_db) stopband_dev = stopband_atten_to_dev (stopband_atten_db) desired_ampls = (0, gain, 0) @@ -75,21 +83,24 @@ def band_pass (gain, Fs, freq_sb1, freq_pb1, freq_pb2, freq_sb2, taps = filter.pm_remez (n + nextra_taps, fo, ao, w, "bandpass") return taps - -## Builds a band pass filter with complex taps by making an LPF and -# spinning it up to the right center frequency -# @param gain Filter gain in the passband (linear) -# @param Fs Sampling rate (sps) -# @param freq_sb1 End of stop band (in Hz) -# @param freq_pb1 Start of pass band (in Hz) -# @param freq_pb2 End of pass band (in Hz) -# @param freq_sb2 Start of stop band (in Hz) -# @param passband_ripple_db Pass band ripple in dB (should be small, < 1) -# @param stopband_atten_db Stop band attenuation in dB (should be large, >= 60) -# @param nextra_taps Extra taps to use in the filter (default=2) def complex_band_pass (gain, Fs, freq_sb1, freq_pb1, freq_pb2, freq_sb2, passband_ripple_db, stopband_atten_db, nextra_taps=2): + """ + Builds a band pass filter with complex taps by making an LPF and + spinning it up to the right center frequency + + Args: + gain: Filter gain in the passband (linear) + Fs: Sampling rate (sps) + freq_sb1: End of stop band (in Hz) + freq_pb1: Start of pass band (in Hz) + freq_pb2: End of pass band (in Hz) + freq_sb2: Start of stop band (in Hz) + passband_ripple_db: Pass band ripple in dB (should be small, < 1) + stopband_atten_db: Stop band attenuation in dB (should be large, >= 60) + nextra_taps: Extra taps to use in the filter (default=2) + """ center_freq = (freq_pb2 + freq_pb1) / 2.0 lp_pb = (freq_pb2 - center_freq)/1.0 lp_sb = freq_sb2 - center_freq @@ -100,20 +111,24 @@ def complex_band_pass (gain, Fs, freq_sb1, freq_pb1, freq_pb2, freq_sb2, return taps -## Builds a band reject filter -# spinning it up to the right center frequency -# @param gain Filter gain in the passband (linear) -# @param Fs Sampling rate (sps) -# @param freq_pb1 End of pass band (in Hz) -# @param freq_sb1 Start of stop band (in Hz) -# @param freq_sb2 End of stop band (in Hz) -# @param freq_pb2 Start of pass band (in Hz) -# @param passband_ripple_db Pass band ripple in dB (should be small, < 1) -# @param stopband_atten_db Stop band attenuation in dB (should be large, >= 60) -# @param nextra_taps Extra taps to use in the filter (default=2) def band_reject (gain, Fs, freq_pb1, freq_sb1, freq_sb2, freq_pb2, passband_ripple_db, stopband_atten_db, nextra_taps=2): + """ + Builds a band reject filter + spinning it up to the right center frequency + + Args: + gain: Filter gain in the passband (linear) + Fs: Sampling rate (sps) + freq_pb1: End of pass band (in Hz) + freq_sb1: Start of stop band (in Hz) + freq_sb2: End of stop band (in Hz) + freq_pb2: Start of pass band (in Hz) + passband_ripple_db: Pass band ripple in dB (should be small, < 1) + stopband_atten_db: Stop band attenuation in dB (should be large, >= 60) + nextra_taps: Extra taps to use in the filter (default=2) + """ passband_dev = passband_ripple_to_dev (passband_ripple_db) stopband_dev = stopband_atten_to_dev (stopband_atten_db) desired_ampls = (gain, 0, gain) @@ -129,16 +144,20 @@ def band_reject (gain, Fs, freq_pb1, freq_sb1, freq_sb2, freq_pb2, return taps -## Builds a high pass filter. -# @param gain Filter gain in the passband (linear) -# @param Fs Sampling rate (sps) -# @param freq1 End of stop band (in Hz) -# @param freq2 Start of pass band (in Hz) -# @param passband_ripple_db Pass band ripple in dB (should be small, < 1) -# @param stopband_atten_db Stop band attenuation in dB (should be large, >= 60) -# @param nextra_taps Extra taps to use in the filter (default=2) def high_pass (gain, Fs, freq1, freq2, passband_ripple_db, stopband_atten_db, nextra_taps=2): + """ + Builds a high pass filter. + + Args: + gain: Filter gain in the passband (linear) + Fs: Sampling rate (sps) + freq1: End of stop band (in Hz) + freq2: Start of pass band (in Hz) + passband_ripple_db: Pass band ripple in dB (should be small, < 1) + stopband_atten_db: Stop band attenuation in dB (should be large, >= 60) + nextra_taps: Extra taps to use in the filter (default=2) + """ passband_dev = passband_ripple_to_dev (passband_ripple_db) stopband_dev = stopband_atten_to_dev (stopband_atten_db) desired_ampls = (0, 1) |