New version of QGIS out

The latest and greatest of QGIS is out, version 1.7. A lot of new functionality and improvements, check out the release notes here or download it directly from here.


Start R inside GRASS but keep the terminal prompt

I often run R from within GRASS GIS. For example using R as a scripting language to automate GIS analysis. Or to use statistical models in R on spatial data in GRASS.

I used to open R in the terminal. However, I am using more and more RStudio instead. This has one drawback. When opening RStudio in the terminal (or any other program for that matter), you cannot use that command prompt anymore. Continue reading “Start R inside GRASS but keep the terminal prompt”

GRASS GIS: creating cross products of multiple raster map layers

I am looking at vegetation distribution in east Africa, using a map we have developed based on historical vegetation maps from the region, and I wanted to know the surface area per vegetation type per country. In ‘spreadsheet terms’, I wanted to create a cross- or pivot table. GRASS GIS offers several options to do this. Note that below I am using the examples provided in the help files of the functions. Check out these help files for further details. Continue reading “GRASS GIS: creating cross products of multiple raster map layers”

Free online textbooks on geospatial and statistical analysis

Geospatial analysis guide

I just found, through this blog, a very nice text book on geospatial analysis; Geospatial Analysis – A comprehensive guide by M. de Smith, P. Longley and M. Goodchild. The book covers a wide range of topics such as “Conceptual Frameworks for Spatial Analysis”, “Data Exploration and Spatial Statistics”, “Statistical Methods and Spatial Data”, “Exploratory Spatial Data Analysis”, “Grid-based Statistics”,  “Spatial Autocorrelation”, and “Network and Location Analysis”. Also very nice, it includes an overview of some of the main spatial statistical packages for R. Continue reading “Free online textbooks on geospatial and statistical analysis”