Visualisation des densités de Zurich, Geneve (en rouge), Bale et Lausanne.
number of lines = density of a city ([hab./km^2])/ 100.
generate size of circle in function of population
radius = map(cities[city].population, popMin, popMax, radiusMin, radiusMax);
http://recodeproject.com/translation/chris-allick-direct-untitled-georg-nees
