This is a user-friendly web app for calculating the P-DFT: a DFT in pitch/midi space (see below). To use the app, enter either pitch names (e.g. "C4, G7, E5") and/or midi numbers
separated by commas and then hit "calculate." Components represent equal divisions of midi space—a higher magnitude for a component means the signal is well divided into *n*-parts (where *n* is the component number).

For more details on the P-DFT, see this presentation by Kahrs and Chiu—proceedings article in Future Directions of Music Cognition.
The magnitudes in the graph above are normalized by the cardinality *f _{0}*.
For examining DFT components separated in a vector space, see Jenn Harding's implementation here.