![Map of France in processing] (http://i60.tinypic.com/sw6y61.png)
- arrows for panning
-
- and - to zoom in and out (defaut = 1x, min = 0.25x, max = 4.0x)
- press 'z' to go back to inital position
- click on a city to highlight it and display its name
- press 'r' to turn off highlighting of all cities
- digits numbers and then ENTER to display only the cities whose population is above the threshold entered
- 1 city = 1 circle
- size of the circle <=> population NB: if a city X is has twice the population of city Y, its area (and not the radius of the circle) will be twice as big
- the density is represented using different shades. The darker, the more populated
- cities are displayed in reverse population order, so that the more populated cities (those whose have the biggest circle) are "under" the others. This ensures that even small cities can be selected