First a confession, I don’t like cartograms, at least not the kind where complex boundaries are warped sometimes beyond recognition. However they do have their place and where there aren’t the extremes in the data a cartogram can be a great data visualisation. It is outliers or extreme values that cause the maps to be distorted beyond usable recognition, and therefore look bad (see below).
Anyway, if your data isn’t going to produce a map like this then you can use the Cartogram plugin in QGIS. This allows you to quickly turn your map into one that removes the misrepresentation of small areas hiding large values. Continue reading “Creating Cartograms using QGIS 2.18”
These maps display the density and distribution of a phenomena over a geographic area. The markers, usually a dot or cross, represent the occurrence or an aggregation of occurrences which are then randomly distributed across distinct regions of the map. Colours can be used to represent different classifications to add an extra dimension to the map.
It is possible to very quickly render any choropleth map you make in QGIS in 3D using the Qgis2threejs plugin. Essentially the plugin allows you to turn a numerical attribute as a “height” for your data. The results from the plugin are outputted as an html page which can be easily shared in a folder or placed on the web for people to view. Continue reading “Creating 3D choropleth or prism map in QGIS 2.18”
Creating proportional symbol maps in QGIS is made very easy in QGIS with two main methods for making them. You can use basic Single Symbol style with the Size Assistant in the Data Defined Override, or you can use the Graduated style and choose Size as the method of gradation. Below is a set of instructions on how to use either method to create proportional point symbols for your map. Continue reading “Creating a Proportional Symbol map in QGIS 2.18”