Following up on my last post, Running Scripts in the Python Console, I created a plugin to simplify running scripts: The Script Runner plugin allows you to add your scripts to a list so they are readily available. You can then run them to automate QGIS tasks and have full access to the PyQGIS...
The QGIS Python console is great for doing one-off tasks or experimenting with the API. Sometimes you might want to automate a task using a script, and do it without writing a full blown plugin. Currently QGIS does not have a way to load an arbitrary Python script and run it1. Until it does,...
The raster calculator allows you to perform mathematical operations on each cell in a raster. This can be useful for converting and manipulating your rasters. Operators include: Mathematical (+, -, *, /) Trigonometric (sin, cos, tan, asin, acos, atan) Comparison (, =, =) Logical (AND, OR) To perform operations on a raster or rasters,...
This week we look at the OpenLayers plugin for QGIS. This plugin allows you to add a number of image services to your map canvas: Google Physical Streets Hybrid Satellite OpenStreetMap Yahoo Street Hybrid Satellite Bing Road Aerial Aerial with labels
This week we take a look at a how to plot a terrain profile using the Profile plugin. The plugin can be used with any raster format supported by QGIS. You can can display profiles from up to three rasters at once, allowing you to compare the results. To illustrate, we’ll create a simple...
This week we highlight the Points to Paths plugin, a handy way to convert a series of points into line features. This plugin lets you “connect the dots” based on an common attribute and a sequence field. The attribute field determines which points should be grouped together into a line. The sequence field determines...
QGIS has a lot of plugins, including over 180 that have been contributed by users. If you aren’t using plugins, you are missing out on a lot that QGIS has to offer. I’m starting what I hope to be a regular feature: Plugin of the Week. This week we’ll take a look at Time...
One of the difficult things to track in the open source world is the number of people who actually use your software. In the proprietary commercial world you have licenses, invoices, and so forth. In the case of QGIS, we can track the total number of downloads from qgis.org, but this doesn’t represent the...
This post is for those of you that build QGIS on a regular basis and want to keep up with everything going on in the current release branches (1.7.2 and 1.8) as well as the master branch that will eventually become version 2.0. While you can do all your work in one clone, this...
The Plugin Builder allows you to quickly create a skeleton Python plugin by generating all that boring boilerplate that every plugin requires. Here is a short video showing how to create, compile, and install a new plugin. For more information, see QGIS Workshop Documentation and the PyQGIS Cookbook.
