Greadability.js: Graph Readability Library

I developed an open source library to calculate graph layout quality metrics to help me evaluate graph layout algorithm research (see d3-force-reuse and d3-force-sampled). The metrics are useful for automatically estimating which layout is better, but I also showed a proof of concept using them to automatically find higher quality layouts.

I included four global graph readability metrics, although it could be extended to include additional metrics:

Edge crossings measures the fraction of edges that cross (intersect) out of an approximate maximum number that can cross.
Edge crossing angle measures the mean deviation of edge crossing angles from the ideal edge crossing angle (70 degrees).
Angular resolution (minimum) measures the mean deviation of adjacent incident edge angles from the ideal minimum angles (360 degrees divided by the degree of that node).
Angular resoluction (deviation) measures the average deviation of angles between incident edges on each vertex.

Live examples