Digital Geography

Military Expenditure on a map

Screenshot from 2014-07-17 14:34:15

Statistical data for a geographer is fun! War is not! Regardless what you think of the military it never hurts to be informed, so… Lets play a bit with military expenditure statistics. I’m using data from SIPRI (Stockholm International Peace Research Institute), which covers military expenditure for regions and countries based on for instance GDP. The data is in Excel format (.xlsx) which is a problem for QGIS, so it has to be converted to a format that QGIS understands. First however some other issues must be addressed. In order to use the years as field names they must be…

regular spaced points… interpolation madness…

rasterized point shapefile in QGISThe geodata department of the city of Berlin offers a great portfolio of free geodata for everyone to use. One dataset is the result of some LIDAR measurements and is offered as a txt with x,y and d values. This is commonly known as xyz data but should not be mistaken as a simple whatever-delimited text file. This dataset is regular spaced and therefore can be threatened easily with QGIS. But let me first show you some interpolation results which can be produced as well. Interpolational madness If you want to create raster data from a point shapefile or a…

reproject and filetype change in python/pyqgis for QGIS plugin

featured_2In my current work on the qgis2leaf plugin I had the idea to place raster data on a leaflet map as an image overlay. With this in mind and looking at a webmap I needed to consider a good filesize, a strict projection of EPSG:4326 and a strict filetype as well. So decision was: projecting everythin to EPSG:4326 and changing file type to *.jpg. I know, how to do this in the Terminal and in QGIS. But what options do you have using python/ pyqgis only? Terminal For doing this work in the terminal/shell/command line the one and only choice…

Top 5 QGIS Plugins

GeoSearch - Routes

I have been using QGIS 2.2 for most of my GIS work for about 3 months now, so I have noticed that I keep on using some plugins over and over and I really wouldn’t be able live without them. So here is a list of my favorite top 5 QGIS plugins! Top 5 QGIS Plugins 1. OpenLayers plugin It was love at first use for the OpenLayers plugin.  It allows the user to load basemap from a different provides like Google, Bing, Yahoo, OSM (OpenStreetMap), Apple (I have NO idea what someone would want it) and Stamen. Now I…

Vintage Themed Maps in QGIS

Vintage_QGIS_Burn

Vintage Design in QGIS 2.2 Hello again! Thanks for taking a look at this post on how to create a Vintage Themed Maps in QGIS 2.2. Now for this process I am using QGIS 2.2 on Ubuntu 14.04, I only mention this because I have never compared the Linux and Windows version to see if there are any difference between the two versions. Furthermore, I would like to state that I originally the idea for this post from this Blog last year, so please take the time to look at it. Also, if you haven’t looked at my original post…

ILWIS GIS – Tutorial I [Introduction]

ILWIS Logo

Today I’ll start with a new series of tutorials for an open Source GIS called “ILWIS GIS“. ILWIS is the short term for “Integrated Land and Water Information System” developed at the ITC Enschede and distributed under the GNU General public license as open Source GIS since 2007. It’s purposes is designed for geoecological questions. It can handle both, vector- and rasterdata.     If you’re interessted in ILWIS you can download the newest version here: http://52north.org/communities/ilwis/ilwis-open/download. The software package is available for the following operation systems: Windows and with the use of additional software on Linux and Mac OS X. The language…

Les outils de GRASS sous Quantum Gis

Quantum Gis intégre de nombreux outils issus du SIG GRASS. Cela constitue plus de 200 outils qui sont utilisables directement sous Quantum Gis. Il est possible de croiser les outils disponibles sous Qgis et sous GRASS afin d’effectuer des traitements de données poussés. Passage de Quantum Gis à GRASS Pour pouvoir utiliser les outils de GRASS, il faut d’abord créer un nouveau dossier de travail GRASS. Pour cela, Qgis intégre une barre à outils GRASS. Pour créer un nouveau dossier GRASS, selectionnez cette icône. Ensuite, définissez l’url du dossier. Désormais, vous allez pouvoir gérer, créer et éditer des fichiers raster…

create point density raster in QGIS

results raster iso lines contour QGIS

In some applications you want to calculate the density of points. It sounds very easy and in fact it is using QGIS. Let me show you how. Especially, let me show you how to do this with the heatmap plugin in QGIS. Prerequisities You will need the common installation of QGIS 2.0.1 Dufour and an installed heatmap plugin (see how to install a plugin here). We will use some field data from Indonesia with 500.000 data points. You may download the data (12MB) we will use here. The doing Fire up QGIS and set the CRS of the project according…

QGIS 2.2 and its new features

The last update of our beloved QGIS 2.0.1. version Dufour was a giant leap for a grown GIS and the next step forward is in sight. Thanks to Mrs. QGIS herself (a.k.a. Anita Graser a.k.a. underdarkGIS) I came across an overview of the changelog for QGIS 2.2 on Linfiniti.com. multithreading We probably all have a multicore CPU available at our notebooks and workstations. So why not use them and let them do serious GIS business instead of running idle and having a cup of tea? QGIS with multithread support was apparently available on some special professional versions of QGIS but…

create 3D visualizations: QGIS, GRASS and NVIZ

meine_möglichkeit_mit_NVIZ

3D is soooo cool… Okay let’s be honest: the exciting times of Second Life are gone and the Oculus Rift is still not in sight in the end-user stores. But it is and was always cool to create you own 2.5D (we are using GIS not CAD, you know) visualization and make beautiful graphics for your papers or posters. It was always a big drawback for QGIS that ArcGIS was and is so good with ArcScene. But we’re proud users and we’ll use NVIZ. Let me show you how.