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A new search engine to search the R documentation
Just to quickly share this great new website where you can search the documentation of all R packages and functions available on CRAN (6688 R packages and 136342 R functions at the moment of writing!)....
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Installing Google Earth on Ubuntu 14.04
Since Ubuntu 13.10 Google earth cannot be installed out of the box on Ubuntu 64-bit systems because it requires the deprecated ia32-libs package. The previous solution I wrote about, for Ubuntu 13.10,...
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Using GDAL from within QGIS: trouble shooting
Some notes to self about steps I had to take to make GDAL work from within QGIS. Both where compiled from source and run without problems. However, there are still a few issues with running gdal from...
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Stable GRASS GIS 6.4.4 released
A new stable version GRASS GIS 6.4.4 has been released. It sports various bug fixes and a number of new features. Go here for more information. You may be aware that there is also a GRASS GIS version...
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QGIS 2.4 is out
Just a few days after the release of GRASS GIS 6.4.4, now the latest and greatest QGIS Chugiak. And this new version comes with a whole bunch of improvements and new features. Check out this nice...
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Sampling raster values at point locations in QGIS – an update
In a by now fairly old post I described how to sample raster values at point location in QGIS. The method I described used the ‘Point Sampling Tool’ addon. However, the function creates a new point...
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Spatialite 4.0 is out
The release of Spatialite 4.0 was just announced on the Spatialite user group. You can download it from the Spatialite website. And while you are on the website, check out the page about switching to...
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Stratified random sampling in GRASS GIS
There are various options to create a vector or raster layers with random sample points, including v.random, r.random and r.random.cells. The first two generate random points within the defined region....
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Stratified random sampling in QGIS
In my previous post I described how you can create a random stratified sampling using GRASS GIS. Unlike in GRASS GIS however, QGIS has a dedicated tool to do this. You can find it under ‘research...
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Import MODIS data in GRASS using r.in.gdal
NASA offers access to its MODIS and ASTER data sets through Reverb|Echo. The data comes in HDF format and uses the Sinusoidal grid tiling system. If your gdal is compiled with HDF4 support (use...
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Check out the new Landcover Polygon overlay function in the LecoS QGIS plugin
The author of the QGIS plugin LecoS came up with a new feature which might come in handy for some of you: a polygon overlay tool. This tool can extract raster values and save them directly to the...
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Improved r.mask in GRASS GIS 7.0
I am mostly using GRASS GIS 7.0, which is the development version. Main reason I started to use this version was the better (faster) vector handling. But there are many other new features and...
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Calculating the raster cell area of an unprojected raster layer
What if you get a raster layer with number of people per raster cell, like for example the population layer from Afripop, and you want to convert it to a population density layer? Well, obviously, you...
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New release candidate for GRASS 6.4.3 is out
The second release candidate of stable release 6.4.3 is available now. It contains a good number of improvements and especially stability fixes, see here for more details.Filed under: GRASS GIS,...
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Looking for a pdf reader with good annotations options
I read my articles on my (Android) tablet or on my computer (Ubuntu 12.10). On both, I want to be able to add notes and underline and highlight text. For Android there are various apps that allow you...
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Find Latitude and Longitude Values in Google Maps
Getting the coordinates of a location on Google maps isn’t as straight forwards as one may expect. But, as usual, if you know how, it is easy enough. And, there are actually several ways. What’s here?...
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Sum up values of neighbouring polygons – a GRASS GIS approach
How to sum up values of neighbouring polygons in QGIS? This question was asked on gis.stackexchange, with two interesting answers. One answer explains how to use Spatialite and SQL to achieve this. The...
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A quick look at the new GRASS Map Swipe Tool
I have just been trying out the new GRASS Map Swipe tool For now it is available in GRASS 7.0 but I understand it will be backported to GRASS 6 after some testing. The tool allows GRASS users to...
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Point coordinates to polygon – part I
Articles about field studies sometimes (but not always unfortunately) contain coordinates delimiting the boundaries of the field study. What if you want to view those boundaries in e.g., Google Earth?...
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Point coordinates to polygon – part II
In my previous article, I showed how you can convert point coordinates into a polygon vector layer in QGIS. So how about GRASS GIS? Like in my previous post, let’s assume you have a text file with two...
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