butterworth 0.0.3

Real-time digital butterworth IIR filter

butter

Python implementation of the digital butterworth IIR filter

Dependencies

• numpy – used for its math modules and fast array calculations

• numba – used to increase calculation speed

Basic Usage

Importing the Butter module:

from butterworth import Butter

Creating the Butter instance for a lowpass butterworth filter with cutoff frequency 1000Hz and rolloff frequency 48Hz for data taken with sampling frequency 44100:

filter_ = Butter(btype="Lowpass", cutoff=1000, rolloff=48, sampling=44100)

Sending sample data into filter and retrieving the filtered data:

data=[1.0, -2.0, 3.0, . . . .]
filtered_data = filter_.send(data)

Retrieving forward-backward filtered data for the accumulated data:

data1=[1.0, -2.0, 3.0, . . . .]
filtered_data = filter_.send(data1)
data2=[-1.0, 2.0, -3.0, . . . .]
more_filtered_data = filter_.send(data2)
forward_backwards_filtered_data = filter_.filtfilt()