Skip to main content

Efficient FIR realtime filter

Project description

An efficient finite impulse response (FIR) filter class written in C++ with python wrapper.

The class offers also adaptive filtering using the least mean square (LMS) or normalised least mean square (NLMS) algorithm.



If you want to install it via pip you first need to install the fir1 filter binaries:

sudo add-apt-repository ppa:berndporr/usbdux
sudo apt-get update
sudo apt install fir1
sudo apt install fir1-dev
Then install the python package with pip::
pip3 install fir1

You can also install from source:

git clone
cd fir1
cmake .
make install
python3 install


There is a pre-compiled package which can be installed via pip:

pip3 install fir1

If you want to compile from source you first need to build the static fir windows library which is called fir_static.lib. Open the command line and type:

cmake -G "Visual Studio 15 2017 Win64" .

Then start Visual Studio and build fir.sln. Go back to the command line and type:

python install


Realtime filtering

The filter is a realtime filter which receives samples one by one so it can process data as it arrives from an ADC converter. This is simulated here with the for loop:

import fir1
b = signal.firwin(999,0.1)
f = fir1.Fir1(b)
for i in range(len(noisy_signal)):
    clean_signal[i] = f.filter(noisy_signal[i])

The constructor Fir1() receives the filter coefficients (= impulse response) and then filtering is performed with the method filter().

LMS adaptive filter

Please check the C++ code for examples and the main github page. The functions are identical.

Project details

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Files for fir1, version
Filename, size File type Python version Upload date Hashes
Filename, size fir1- (27.6 kB) File type Wheel Python version 3.6 Upload date Hashes View hashes
Filename, size fir1- (30.6 kB) File type Egg Python version 3.6 Upload date Hashes View hashes
Filename, size fir1- (6.1 kB) File type Source Python version None Upload date Hashes View hashes

Supported by

Elastic Elastic Search Pingdom Pingdom Monitoring Google Google BigQuery Sentry Sentry Error logging AWS AWS Cloud computing DataDog DataDog Monitoring Fastly Fastly CDN SignalFx SignalFx Supporter DigiCert DigiCert EV certificate StatusPage StatusPage Status page