Digital filtering is a widely used technique that is common in many fields of science and engineering. Filters remove unwanted signals and noise from a desired signal. There are many different kinds of filters, including low pass, high pass, band pass and band stop filters. In just the category of low pass filters, there is a large collection of filters that famous engineers and mathematicians have invented, including Hanning, Hamming, Blackman, Kaiser and Tukey windows. In this post, I will show you how to use Matlab’s filter function to remove a high frequency signal from a desired signal.