Plot of temporal data sets in GRASS GIS

One of the new modules in GRASS GIS 7.03 (RC1) is g.gui.tplot. It is part of the temporal data processing framework (TGRASS) introduced with GRASS GIS 7.0 and lets you plot the values of one or more temporal datasets for a specific point. It furthermore allows plotting data of vector dataset for a defined categories and attribute. In this post I’ll use the tool to plot changes in the annual mean temperature and annual minimum temperature of the coldest month in the last century, using the CRU climate data set. First I’ll provide a brief overview of how to import and prepare the data and finally how to plot a time series using the g.gui.tplot module. Continue reading “Plot of temporal data sets in GRASS GIS”

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GRASS GIS 7.0.2 released

For those who haven’t seen it yet, GRASS GIS 7.0.2 has been released! See here for the announcement and here for a detailed overview of all the changes (over 190 of stability fixes and improvements since GRASS GIS 7.01).

For those still using GRASS GIS 6.4, GRASS GIS 7 offers a strongly improved interface, a considerable increases in speed and efficiency, support for huge files, and a long list of new modules to analyse raster and vector data, including a full temporal framework. Also important, as a stable release series, 7.0.x enjoys long-term support.

As usual, a great thanks to the developers!

GRASS GIS categorical raster layers in QGIS

With the QGIS GRASS plugin, you can easily open a GRASS raster layer in QGIS. One disadvantage, however, is that if your GRASS layer has category labels, these will not show in the QGIS legend. See for example the landuse layer in the North Carolina data set,  opened in QGIS in the screenshot below.

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It isn’t too much problem to define the labels in QGIS if you have few categories only, but what if your map in GRASS has many categories, all neatly labelled in GRASS. Sure you don’t want to add those category labels manually again in QGIS?

I don’t, so I wrote a small GRASS GIS addon, r.category.trim, that export the attribute table and colour table in GRASS GIS as a QGIS colour map file.

Continue reading “GRASS GIS categorical raster layers in QGIS”

First release candidate of the upcoming GRASS GIS 7.0.2 version

Fresh from the press, that is, the GRASS email list: The first release candidate of the upcoming GRASS GIS 7.0.2 is out. This upcoming stability release provides a series of stability fixes and manual improvements. This first  release candidate GRASS GIS 7.0.2RC1 provides 160 fixes and improvements. So first a great thanks for all the hard work of the developers!

There are also two new modules: r.import and v.import. Continue reading “First release candidate of the upcoming GRASS GIS 7.0.2 version”

The QGIS GRASS plugin is back

For me, one of the killer features of QGIS has always been the integration with GRASS GIS. With the GRASS GIS plugin, introduced about 10 years ago, QGIS basically provided an alternative interface for GRASS GIS. Sadly, it didn’t work well with GRASS GIS 7. So you can imagine how happy I was to see this crowd funding campaign, started in March this year by Radim Blazek, author of most parts of original GRASS plugin implementation, to upgrade the plugin. Continue reading “The QGIS GRASS plugin is back”