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Exploring Digital Filter Design with Python

If you analyze data chances are you need to use digital filters. The theory and practice of filter design and filter characteristics is well developed and requires some math background. If you do not have the patience to go through all the math the second best thing is to look at filter designs to get an intuition of how filter type and order translate into filter characteristics.

I've written a simple Python script using the Pylab and Scipy packages that allows you to interactively 'draw' a filter characteristic and see the filter design results from various algorithms.

The amplitude and phase characteristics, and the filter order are plotted and the coefficients are shown in the command window.

To play with this educational tool go to the neurapy repository on git hub and grab this script. Run in from ipython and explore the world of digital filter design.
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