Filters, Differential Equations, and Distributions

Filters for functions have been studied in Lessons 1, 2, 24, and 25. We are going to recast and complete this analysis in the light of what we now know about distributions. We will see that the basic tools developed so far, namely, convolution and the Fourier transform, play an essential role in the study of generalized filters, in the same way they did in the study of filters for functions.