Friday, December 18, 2015

Visualization of large multi-criteria result sets with Bokeh

In http://yetanothermathprogrammingconsultant.blogspot.com/2015/12/visualization-of-large-multi-criteria.html we showed some 3D (interactive) plots using plot.ly. Here we look at a pair of 2D projections in Bokeh:

These are 2D plots of a large set of non-dominated (Pareto optimal) solutions with three objectives (Minimize Cost, Minimize Weight and Maximize Performance). As usual these projection plots are a little bit misleading. We can demonstrate this using an advanced feature of Bokeh: linked plots. When we select some points in the left plot, automatically the corresponding points are shown in the right plot:

This is also a Javascript based library, so these interactive plots live in a browser. With WebGL enabled, they render very quickly and the User Interface is quite smooth. See http://yetanothermathprogrammingconsultant.blogspot.com/2016/01/internet-explorer-webgl-bug.html for some problems with Internet Explorer.

With some effort we can color the points in these 2D plots according to the third dimension: