This page consists of useful pieces of code I've written. Feel free to use and modify for your own projects. Contact me at drew [at] drewpendergrass.com if you find any errors.

• filter_functions.R: Meant for use in conjunction with the TDAMapper package in R, these are useful filter functions I've collected from a handful of papers and used in my own research. For more information on this approach to topological data analysis, see the second half of "Topology and Data" (2009) by G. Carlsson in the Bulletin of the American Mathematical Society.