A great way to try out open source GIS software

I just came across an email thread on the QGIS email list that mentioned OSGeo-Live. This is a “self-contained bootable DVD, USB thumb drive or Virtual Machine based on Xubuntu, that allows you to try a wide variety of open source geospatial software without installing anything”. Worth exploring if you are looking for new great geospatial software.


Check out this article ‘Let the four freedoms paradigm apply to ecology’ (but don’t get it from ScienceDirect)

There is an interesting letter (Let the four freedoms paradigm apply to ecology) in Trends in Ecology and Evolution by Duccio Rocchini and Markus Neteler arguing that science should use open source software. Basically, using open source software will help researchers to test, reproduce and build upon work of others, while being (more) sure that the code / algorithms they are using are robust and reliable. Continue reading “Check out this article ‘Let the four freedoms paradigm apply to ecology’ (but don’t get it from ScienceDirect)”

Split strings in SQLite

I am just back from vegetation survey in Kenya and Uganda. Before starting with the analysis, I will have to go through the more boring data entry and organization. I will use a Spatialite database to store all the data as it plays nicely together with QGIS as well as R. For example, importing the waypoint data (gpx format) into a spatialite database is a breeze with the QSpatialite plugin for QGIS.

One problem is that data and time in the gpx file are given in one field, in the form ‘2011/11/01 5:49:41+00‘. There are various ways I could split this before importing in the SQLite database, e.g., using R or a spreadsheet. But how to do this after importing the data in the Spatialite database? The date + time are imported in the field ‘time‘. Continue reading “Split strings in SQLite”

New “Control Rendering Order” Option in QGIS

I just installed the latest QGIS development version (build 1.9.90-Alpha), and one of the changes I noticed was the option “Control rendering order” in the layers pane. I had to Google to check out what this new option was about. As Darren Cope explains in his blog, it allows you to decouple the way layers are organized in the legend (“Layers” pane) from the order they are rendered (drawn) on the canvas (controlled via the “Layer order” pane.). Continue reading “New “Control Rendering Order” Option in QGIS”