As of May 31, 2023, we have updated our Code of Conduct.

Questions tagged [four-color-theorem]

the four color map theorem, states that, given any separation of a plane into contiguous regions, producing a figure called a map, no more than four colors are required to color the regions of the map so that no two adjacent regions have the same color.

Filter by
Sorted by
Tagged with
3 votes
1 answer

How to apply the Four Colour theorem on GeoJSON feature collection with Leaflet

Imagine you have a GeoJSON feature collection of adjacent colored polygons presented in a Leaflet map; in the present case the parishes of the city of Lisbon fetch('
João Pimentel Ferreira's user avatar
3 votes
1 answer

Color polygons in different colors using geotools

I need to color polygons in different colors, ensuring that polygons sharing boundaries do not have the same color (the well-known four color theorem). Is there a way to do that using GeoTools?
julien's user avatar
  • 10.1k
4 votes
1 answer

How to ensure different colors for surrounding polygons?

Currently in the client I have an array of colors that is looped through for a given set of geometry features. Features are grouped together on the map and each group has a color assigned to it. It ...
Don's user avatar
  • 725
7 votes
2 answers

Distinctly color world map by language in QGIS 2.4

For a map of Wikipedia language prefixes, I need to color a map by a country's value in the 'language' column. I. e. all countries with the same language worldwide should share a color, which they ...
Pikaro's user avatar
  • 71
17 votes
3 answers

Achieving four color theorem for QGIS

I recently looked at Applying four colors theorem in polygon map using ArcMap which relates to this topic but as far as I can tell there is currently not a working plugin or script for QGIS 2.0 to ...
clhenrick's user avatar
  • 1,775
1 vote
1 answer

Automatic four-colour (political boundary) rendering with PostGIS

This is probably a long shot, but is there a way to automatically select colours for neighbouring regions using the four colour theorem, in PostGIS? The data I'm using is suburb boundaries in ...
Steve Bennett's user avatar
21 votes
4 answers

Applying four colors theorem in polygon map using ArcMap

I need to apply the four colors theorem in a polygonal shape in a way that I do not need to choose manually each color to put in each region. I wish to knows if there is any extension, plug-in, script ...
NaN's user avatar
  • 313