Mapping Your GIS Data

Joey Bernard — Wed, 09 Oct 2013 20:36:36 +0000

I've already looked at some GIS applications available on Linux. Programs like GRASS and qgis provide a full set of tools to do GIS. Sometimes, that's really overkill though. You may just want to display some data geographically and create a map. For those cases, there is Thuban, an interactive geographic data viewer.

Most distributions should have a package available within their package management systems. If not, you always can download the sources and build it from scratch. It does depend on Python, among several other libraries, so you need to do a bit of a dependency dance. Binary downloads even are available for Windows and Mac OS X, so you can point your non-Linux friends to them.

If you don't already have data of your own, sources of public-domain GIS data are available on-line. Here are a couple: http://www.naturalearthdata.com/features and http://wiki.openstreetmap.org/wiki/Shapefiles. The files available on these sites will get you started with SHP files that contain at least basic features for most of the world.

Thuban is not as flexible as full-fledged GIS software and cannot handle very many data file formats. You can use SHP files, DBF database files and various image file formats. In the screenshots for this article, I simply grabbed several of the data files available on-line.

When you start Thuban, you end up with a completely blank slate (Figure 1). The first step is to start a new session, which you can do by selecting the menu item File→New Session (not much will change on the screen). In order to start building your map, you need to add layers that can be manipulated. I started by selecting the menu item Map→Add Layer and adding in an SHP file to give me the basic geographic attributes for my home province of New Brunswick (Figure 2). This includes several different geographical items, such as water, river banks and parks. The default display is not very interesting yet (Figure 3).

Figure 1. Starting Thuban gives you a blank slate.

Figure 2. Adding a new layer opens a file selection dialog where you can choose an SHP file.

Figure 3. By default, Thuban just displays all of the data with a single symbol color.

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