df2#

class diffsptk.SecondOrderDigitalFilter(sample_rate: int, pole_frequency: float | None = None, pole_bandwidth: float | None = None, zero_frequency: float | None = None, zero_bandwidth: float | None = None, ir_length: int | None = None)[source]#

See this page for details.

Parameters:

sample_rateint >= 1: The sample rate in Hz.
pole_frequencyfloat > 0 or None: The pole frequency in Hz.
pole_bandwidthfloat > 0 or None: The pole bandwidth in Hz.
zero_frequencyfloat > 0 or None: The zero frequency in Hz.
zero_bandwidthfloat > 0 or None: The zero bandwidth in Hz.
ir_lengthint >= 1 or None: The length of the truncated impulse response. If given, the filter is approximated by an FIR filter.

forward(x: Tensor) → Tensor[source]#

Apply a second order digital filter to the input waveform.

Parameters:

xTensor [shape=(…, T)]: The input waveform.

Returns:

outTensor [shape=(…, T)]: The filtered waveform.

Examples

>>> x = diffsptk.ramp(4)
>>> df2 = diffsptk.SecondOrderDigitalFilter(16000, 100, 200, 1000, 50, 5)
>>> y = df2(x)
>>> y
tensor([0.0000, 1.0000, 2.0918, 3.4161, 5.1021])