interactive Javaplex demo with barcodes
What is it?
Javaplex is a program for running computations in topological data analysis. See https://github.com/appliedtopology/javaplex, or the tutorial at https://github.com/appliedtopology/javaplex/wiki/Tutorial. Javaplex can be set up to run within Processing, an IDE and programming language well-suited for visualization. The Javaplex download comes with a sample Processing sketch called javaplexDemo.pde.
This repo contains the files needed to run InteractiveJPDwB.pde, a Processing sketch written by Luke Wolcott that builds on javaplexDemo.pde.
InteractiveJPDwB allows the user to create a 2D data set with mouse clicks. It simultaneously computes and outputs the persistent homology barcode, allowing the user to explore the relationship between data and barcode.
Screenshots and screencast
For a demonstration, check out http://forthelukeofmath.com/InteractiveJPDwB/screenshots.html to see a screencast of InteractiveJPDwB and its main features, along with screenshots and explanations. The screenshots are also in a folder in this repo.
How do I use InteractiveJPDwB?
For the time being, you need to download both the sketch "InteractiveJPDwB.pde" and the "data" folder into a common directory. Open InteractiveJPDwB.pde with Processing, and run the sketch. Instructions appear at the bottom of the screen.
What is new?
The original javaplexDemo.pde allowed the user to create a 2D data set with mouse clicks. The left and right arrows would fill in the Vietoris-Rips complex with lines and triangles. The persistence intervals could be computed, and would print to the sketch window.
The main contribution of InteractiveJPDwB is to generate and plot a barcode from the persistence intervals, and to update the barcode whenever the data set is changed. It allows users to remove points by SHIFT-clicking. It adds the pre-loaded data sets #1-4. One can save up to four data sets and easily load them, allowing quick side-by-side comparison of barcodes.