Data mining my email with Java and then using D3.js to visualize it.
I started selling Minecraft server mods in 2015. My email inbox was cluttered with Paypal payment receipts and I wanted to develop a way to aggregate all of that data into some sort of useful visualization. I ended up writing a Data Mining Utility that scans a Gmail inbox and parses out Paypal payment information into organized objects. Once the data set was complete, I was able to isolate the information and display some interesting statistics.
