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.

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1answer
137 views

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?
3
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1answer
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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 ...
7
votes
2answers
2k views

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 ...
10
votes
3answers
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Four color theorem for QGIS? (4 colour)

I recently looked at some other posts relating to this topic but as far as I can tell there is currently not a working plugin or script for QGIS 2.0 to achieve a four color theorem for styling polygon ...
1
vote
1answer
310 views

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 ...
19
votes
4answers
4k views

How to apply the four colors theorem in a polygon map in ArcGIS/ArcToolBox automatcally?

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 ...