Author Archives: pvanb

About pvanb

I am a tropical forest ecologist with a focus on spatial and temporal patterns and processes at population and ecosystem level. I am furthermore very interested in issues related to conservation and sustainable use of biodiversity and natural resources under current and future climates. I have worked in the Middle East (Syria and Lebanon) and South America (Brazil) and in Eastern Africa (Kenya).

Update of Zim-wiki export template for an adaptive website

A short note that I updated my export template for a adaptive website to work with Zim 0.61. You can find it on my github page. It is very much work in progress, but perhaps it will be useful to somebody.

Examples of websites that were created using this template are, and

UK to adopt ODF as standard format

This could be an important move, theĀ UK adopts ODF as standard format for government documents. Stated reasons; the open standards will reduce the cost incurred by users and it will be easier for them to work with the government when they use ODF.

Perhaps this may also compel Google to support ODF in Google Docs (ironically, the latest MS Office products seems to support ODF better than Google Docs, but anyway..).

GRASS GIS 7.0.0 beta 3 is out, bringing further fixes and improvements

GRASS 7 sports very significant improvements and numerous new functions. For example, the improved graphical user interface makes it much easier to carry out complex GIS operations and handling of vector data has become much faster and more efficient with very large files. There is a large number of new analytical raster and vector modules and existing modules are now much faster (some even 1000 x faster). Beta 3 ships 390 fixes and improvements with respect to beta 2. For more details, go to

Version 0.61 of Zim is out

A new version (0.61) of the Zim desktop wiki, my favourite notebook / project organizer, was released today. Apart from a large number of under-the-hood improvements, it sports a number of very welcome new features.

  • A more flexible export, allowing to export pages recursively. I.e., apart from the whole notebook or a single page, you can now also export sub-nodes. This was very high on my wish-list, great!
  • And it is getting better with another point on my wish-list now implemented; the option to export multiple pages to a single output file.
  • Export templates now support many more instructions and expressions. I had a quick look at the help file, and it looks like this has become a very powerful tool, albeit with a steep learning curve. Let’s see how this can help to further improve my current export template for a adaptive website.
  • New plugin for editing sequence diagrams (sound interesting)
  • The “tags” plugin was changed to show full page paths in the per-tag view.
  • Floating ToC, see screenshot below.
  • Possibly my favourite new plugin, the Source view plugin, which allows inserting ‘code blocks’ in the page that will be shown as emdedded widgets with syntax highlighting, line numbers etc.

You can download the new version from the Zim wiki website.

The new floating ToC widget in action (Zim version 0.61)

The new floating ToC widget in action (Zim version 0.61)

Exporting your GRASS raster using r.out.gdal? Check the createopt options!

GRASS GIS can export your raster layer in most common (and quite a few less common) data formats using theĀ r.out.gdal function (menu: file – export raster map – common raster formats). Exporting is so simple that you may forget that depending on the output format there are different options to optimise your output raster layer. Continue reading

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 layer, which only contains the values extracted from the raster layer. None of the fields in the original point layer is copied to the new one. It is possible to join the attribute table of the new vector point layer with the original attribute table afterwards using a spatial join as explained in that post. However, this will not work if your point data includes points with exactly the same coordinates.

Since I wrote that post, QGIS has come a long way. Continue reading