“Einigkeit und Recht und Frei-ei-heit…!”
But before we get to that, as explained earlier, there are different levels in my ZIPScribble Maps:
- Level 1 ZIPScribble Map: Only the first digit of the postcode is compared. Thus, a discontinuity is detected, for example, between postal codes 8679 and 9000, but no discontinuity is detected between 8399 and 8400.
- Level 2 ZIPScribble Map: The first two digits are compared. Thus, a discontinuity is detected between postal codes 8679 and 9000 as well as between 8399 and 8400.
- The Level 3 ZIPScribble Map works analogously.
Find below Levels 1 through 3 of the ZIPScribble Map of Germany:
Unlike in France, German postcode regions do not necessarily follow the boundaries of German states (nor actually the boundary between former East and West Germany. Note, however how the state and city of Hamburg (star-shaped feature in the northernmost pink region) and the state and city of Berlin stand out (star-shaped green feature in the north-eastern part).
Also remarkable: the very dense postcode structure in the state of Rhineland-Palatinate (mostly the westernmost purple region and a small part of the turquoise region due south of it)!
On level 2 the cities of Hamburg and Berlin are still salient. Also, Bremen, Hannover, Stuttgart and, a bit less, Munich can be distinguished from their surroundings.
Like in France, level 3 gets rather chaotic…
Also behold the patriotic renditions in black-red-gold:
Note how I had to cheat (introduce orange as a colour) in order to depict all the individual regions. This is an empiric rendition of the four colour theorem which states that you need at most four colours to colour any choropleth map. However, in Germany this is obviously not only at most, but also at least. While I did this coloring, however, I couldn’t help but notice what a special topological structure german postcode regions have. Neither France, nor Italy nor Switzerland have a level 1 postcode region which is topologically connected to almost all other regions!