I want to thank everyone who came to my Mapping the Votes talk at Google. The talk is available on YouTube – with apologies for the small font size in the code samples!
However, here comes two main problems with vectorial map simplification :
1. A polyline (a border in a common map language) is generally shared by at least two elements. For example, a border can separate towns, districts, countries.
2. Vectorial maps are often grouped in many layers, sharing their points. For instance : a group composed of a world map layer, a country map layer, a city limit map layer. The most accurate is obviously the last one but after every simplifications, each map should always be superimposable.
Our program solves these problems and we will explain how we did that in the How it Works section.