New course material on visualising data in R with ggplot2

Hadley Wickham, creator of ggplot2, a R package for data plotting and visualization using R, posted slides, data and code of two short courses on the web. There are 5 sets of slides, covering the following topics: Continue reading “New course material on visualising data in R with ggplot2”


Nice step by step tutorial how to create an Open Source Web Map

Ever wanted to create an open source web map but not sure where to start? The short tutorial ‘Blueprint for Creating an Open Source Web Map‘ by Michelle Ballinger might be just what you are looking for. This tutorial “takes the user through the steps of creating new data, modifying existing data to the map’s specifications, creating style layer descriptors, writing basic HTML, and posting to the Internet”. These steps are done in respectively QGIS, UDig, any text editor and GeoServer. Continue reading “Nice step by step tutorial how to create an Open Source Web Map”

MapTiler to create online maps

For a project a few years ago we created a vegetation map for central and southwest Kenya (see here for more information). The map together with documentation was initially made available on CD-ROM. I also created an online map. Apart from the version mentioned in this post, I also created a version with MapTiler.

MapTiler requires a georeferences image file as input. To export the vegetation map from my GRASS GIS database to a georeferenced image, I used the r.out.tiff function.

r.out.tiff -t input=veg_ethiopia_pnv@vegetation output=vegethiopia.tif

The resulting file can be used in MapTiler to create map mashups for Google Earth, Google Maps or OpenLayer. MapTiler offers a wizard like interface which leads you step by step through the process. Continue reading “MapTiler to create online maps”

TACCIMO – a template for Assessing Climate Change Impacts

Collecting and producing data is one thing, combining it and making it easily accessible and useful for the end-users another.

The Template for Assessing Climate Change Impacts and Management Options (TACCIMO) is a nice example of a Web-based tool that provides land owners, managers, and planners in the United States with the most current climate change science available. Continue reading “TACCIMO – a template for Assessing Climate Change Impacts”

Adding Google or OpenLayers maps to your Desktop GIS

Although Google maps and other online mapping tools become more powerful, it is not always easy or straithforwards to use these tools to combine offline maps with online maps from e.g., Google or Yahoo maps.

Tools like ClickFu in QGIS make it easy to find specific features on a layer in QGIS back in Google maps (see here for an earlier post on ClickFu). But what if you to combine your own layers with the Google, OpenLayer or Yahoo maps in QGIS? Well, you use the OpenLayers plugin. Continue reading “Adding Google or OpenLayers maps to your Desktop GIS”