Filters

A set of filters is also stored in remote side and can be accessed via the uri:

filters://path_filter_definition.filter

Note

for each filter, the equivalent in numpy format is available with the name filter_name_ba.npy instead of filter_name.filter.

Cheetah filter

  • name: cheetah/spike_6k_32taps.filter

  • type: fir

  • description:

    • 32 taps high pass filter with cutoff at 6/32 times the sampling frequency

    • received from Neuralynx; same filter that is used for acquisition

IIR antialiasing

  • name: iir_antialiasing/cheby2_antialiasing_32kHz.filter

  • type: biquad

  • description:

    • 10th order cheby2 lowpass filter with cutoffs at None - 1200 Hz (sampling frequency = 32000 Hz)

    • max ripple pass = None

    • max ripple stop = 80

../../_images/cheby2_antialiasing.png

IIR ripple

  • name: iir_ripple/ellip_ripple_4kHz.filter

  • type: byquad

  • description:

    • 12th order ellip bandpass filter with cutoffs at 150 - 250 Hz (sampling frequency = 4000 Hz)

    • max ripple pass = 0.1

    • max ripple stop = 60

../../_images/ellip_ripple_4kHz.png

IIR ripple low design

Matlab implementation

  • name: iir_ripple_low_delay/matlab_design/irr_ripple_low_delay.filter

  • type: byquad

  • description:

    • 20th order Chebyshev 2 low-ass filter with stop-bands 0-115 and 275-nyq Hz and pass-band 135-255 (sampling frequency = 32000 Hz);

    • max ripple pass = 1

    • Stop-band attenuation (1 and 2) = 40 dB

../../_images/IIR_ripple_matlab_magnitude.png

Python implementation

  • name: iir_ripple_low_delay/python_design/cheby2_ripple_2kHz.filter

  • type: byquad

  • description:

    • 24th order Chebyshev 2 bandpass filter with cutoffs at 115 - 275 Hz (sampling frequency = 2000 Hz)

    • max ripple pass = 1

    • max ripple stop = 40

  • name: iir_ripple_low_delay/python_design/cheby2_ripple_4kHz.filter

  • type: byquad

  • description:

    • 20th order cheby2 bandpass filter with cutoffs at 115 - 275 Hz (sampling frequency = 4000 Hz)

    • max ripple pass = 1

    • max ripple stop = 40

  • name: iir_ripple_low_delay/python_design/cheby2_ripple_32kHz.filter

  • type: byquad

  • description:

    • 8th order cheby2 bandpass filter with cutoffs at 115 - 275 Hz (sampling frequency = 32000 Hz)

    • max ripple pass = 1

    • max ripple stop = 40

IIR spike

  • name: iir_spike/bessel_spike.filter

  • type: byquad

  • description:

    • 4th order bessel bandpass filter with cutoffs at 600 and 6000 Hz (of signal with sampling frequency = 32000 Hz)

../../_images/bessel_spike.png