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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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('https://geoapi.pt/municipio/lisboa/...
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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?
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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