The function DGFT.m implements Algorithm 2 in the following paper:

@ARTICLE{RAGEDGFT, author={R. {Shafipour} and A. {Khodabakhsh} and G. {Mateos} and E. {Nikolova}}, journal={IEEE Trans. Signal Process.}, title={A Directed Graph {F}ourier Transform With Spread Frequency Components}, year={2019}, volume={67}, number={4}, pages={946-960}, doi={10.1109/TSP.2018.2886151}, ISSN={1053-587X}, month={Feb},}

Example_to_run_DGFT.m shows how to simply use the function DGFT to find a set of orthonormal basis vectors having spread modes of signal variation with respect to the underlying network topology.