Spatial packages and Travis

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A number of R spatial libraries have been updated in the last couple of weeks, and this has played havoc with my Travis-CI build. I had still been using Ubuntu Trusty with Travis which uses old versions of libraries like rgdal and rgeos, so I needed to move to updated versions of these. In addition sf has now become a dependency for a number of spatial packages like tmap, and this uses libudunits2-dev which isn’t installed by default.

Spatial microsimulation 101

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I recently gave a presentation for analysts and data modellers at the Department for Work and Pensions (DWP) introducing the spatial microsimulation technique (specifically the IPF flavour), and below are the slides I used (use spacebar to navigate through the slides): Much of the content is based on material from Spatial Microsimulation with R by Robin Lovelace and Morgane Dumont (online content | physical book) and my own rakeR package for R.

Simplify polygons without creating slithers

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When simplifying polygons it’s almost inevitable that you will generate some slither polygons or gaps between the correct polygons. For example, the following image shows two adjoining complex polygons, representing two adjoining administrative areas. Note there are no gaps between the polygons; they are contiguous (the border is between Sheffield and Barnsley LADs, by the way).Original geometries without simplification Now if we simplify these polygons to reduce their complexity using simplify geometries in QGIS, gaps appear between the original two polygons and they are no longer contiguous.

House prices 3d visualisation

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On Saturday (24th September) I participated in the UK Data Service’s Open Data Dive Hackathon. The goal was to use open data to create an artefact or visualisation with the grand prize being the opportunity to have your artefact printed on one of MMU’s industrial 3D printers. I wanted to explore using a QGIS plugin called qgis2threejs to create 3D visualisations using the three.js javascript framework that allows you to render your visualisation in a WebGL-capable browser.

townsendr interactive map

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This week I updated my Townsend Material Deprivation Score project. The update makes townsendr an interactive online map of deprivation that users can simply view in their browser, rather than having to download and run the R code or view only static maps. I think the result is much more intuitive and useful. Making the map interactive is achieved by using Shiny, a technology for R to make interactive charts and plots.

Creating a globe in QGIS

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I love a good bit of map making and I have a bit of time on my hands at the moment, so I followed this tutorial by Steven Bernard to create a globe from a world map in QGIS: The steps are straightforward. The fiddly bit was getting the line endings and indentation correct which are essential in Python, so I copied the text out and created a gist with line endings preserved: