Creates a polyphase FIR interpolating filter.

Parameters:¶

rate: int¶

The interpolation rate \(r\).

taps: 'kaiser' | 'linear' | 'linear-matlab' | 'zoh' | ArrayLike = 'kaiser'¶

The multirate filter design specification.

• "kaiser": The multirate filter is designed using multirate_taps() with arguments rate and 1.

• "linear": The multirate filter is designed to linearly interpolate between samples. The filter coefficients are a length-\(2r\) linear ramp \(\frac{1}{r} [0, ..., r-1, r, r-1, ..., 1]\). The first output sample aligns with the first input sample.

• "linear-matlab": The multirate filter is designed to linearly interpolate between samples. The filter coefficients are a length-\(2r\) linear ramp \(\frac{1}{r} [1, ..., r-1, r, r-1, ..., 0]\). This is method MATLAB uses. The first output sample is advanced from the first input sample.

• "zoh": The multirate filter is designed to be a zero-order hold. The filter coefficients are a length-\(r\) array of ones.

• npt.ArrayLike: The multirate filter feedforward coefficients \(h_i\).

streaming: bool = False¶

Indicates whether to use streaming mode. In streaming mode, previous inputs are preserved between calls to __call__().