Graph Axis Labels Interaction

I've been playing with the idea of a personal journal app that lets you track basic information about mood, sleep quality etc. along with images.

I really admire the work of Nicholas Felton so i thought it would be interesting if the data would be presented in a visual way. As a next step it would also be nice to see changes of the variables over longer timespans and maybe discover relationships between the factors.

Let me know what you think.