Data representation with D3.js

In order to finish a quick project, I need a developer to second me on the javascript part of a data representation. Inspired by the D3.js exemple you can found here ([login to view URL]). the goal will be to display a dynamic pie/donut chart when the user click on a city on a map for specific country (around 5-10 cities). Data set to be displayed will be likely provided in the format of a set of CSV/TSV files (one per city), but as I will take care of this part this can be adapted.