What can Facebook, Amazon and Google teach us? Www2009.eprints.org/73/1/p721.pdf. Force-Directed Graph. This simple force-directed graph shows character co-occurence in . A physical simulation of charged particles and springs places related characters in closer proximity, while unrelated characters are farther apart. Layout algorithm inspired by Tim Dwyer and Thomas Jakobsen . Data based on character coappearence in Victor Hugo’s , compiled by Donald Knuth . Source Code. Sanders Analytics - Twitter Sentiment Corpus.