Plugins for QGIS I use most often.
All of these can be installed automatically by QGIS. Click on Plugins>Fetch Python Plugins. Then search for the plugin, click on its name, and click Install Plugin. Few plugins require a restart.
- MMQGIS – Great for working with CSV files; also merges layers (even if they have differing attributes); has various other useful functions, including converting string data to float data. HasÂ Voronoi diagram function (takes a long time to process).
- fTools – Replicates some of the most basic geographic tools in ArcGIS, like Clip, Dissolve, and Reproject. Can also add X/Y values to point attribute tables that are missing them (if you want latitude/longitude, you must reproject into a coordinate reference system first, like WGS84 [EPSG: 4326]). Unfortunately, there’s little information on what each fTools function does. Below are descriptions:
- Extract Nodes – Create a point at each intersection of vertices.
- Basic Statistics – Generate arithmetic statistics for fields, same as statistics function in ArcGIS. Great for quickly understanding the extent of values in a field (especially numeric values), like mean, max, min, standard deviation, and number of unique values.
- Nearest Neighbour Analysis – More details here.
- Geoprocessing Tools>Dissolve – Combine features based on a shared attribute. For example, all features with an identical STREET_TYPE be combined into a single feature. For example, all “Avenues” will become one feature and all “Boulevards” will become a second feature. Only works on polygon layers.
- DescriÃ§Ã£o em portuguÃªs
- Table Manager
- Open Layers – Embed Google, Yahoo, Bing, and OpenStreetMap layers in your map. See my example.