Last update:
Fri Jan 10 06:30:27 2025
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This is an unofficial recap of the OSGF meeting, based on my recollections having spent 10 hours on IRC and the phone. I’m sure the foundation will release an official version of the day’s events, so take my comments with a grain of salt. As I stated in an earlier post, the name was chosen early on and without an excessive amount of debate. OSGF rolls off the tongue rather easily and has a nice ring to it.
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 Installing the Plugin The OpenLayers plugin is installed like all other Python plugins. From the the Plugins menu in QGIS, choose Fetch Python Plugins.
One of the challenges in any open source project is accepting contributions from people that don’t have, need, or want access to your centralized source code repository. Managing repository accounts for occasional or one-time contributors can be come a bit of an administrative issue. To date, the QGIS project has accepted one-time or occasional contributions through patches submitted via a help ticket. To make it easier for you to contribute to QGIS, we have created a clone of the Subversion repository on GitHub.
The PyQGIS Programmer’s Guide is now available in both paperback and PDF. A sample chapter is also available for download. The book is fully compatible with the QGIS 2.x series of releases. See locatepress.com for details.
One of the often overlooked support mechanisms for Open Source GIS applications is Internet Relay chat, better known as IRC. Many OS GIS projects maintain an IRC presence. Often times you will find the project developers hanging out on the channel and willing to answer questions (more about that in a bit). Speaking personally, the Quantum GIS project has used IRC for project coordination, communication, and user support for several years.
It amazes me how people fail to communicate when speaking about technical matters. I’m sure you have heard this refrain: “My computer doesn’t work” or perhaps “Program XYZ blows up”. Ok, in the general sense there is some information being conveyed here. Often times the speaker is not merely providing a fact but asking for help in a very oblique manner. Before you think I’m picking on the poor newcomer, I’m not.
After a rather long lapse, I had the occasion to write some Java code recently (mainly because it didn’t look like Howard’s PySDE was functional). I didn’t like it. Not to start a language flame war, but after using Python almost exclusively for 6 months, I found Java to be cumbersome. I kept thinking “if it were Python I could do it this way”. Sending an email from Java–frightening. From Python–simple.
Plugin Builder 2.8 is now available. This is a minor update that adds: Suggestion for setting up an issue tracker and creating a code repository Suggestion for a home page Tag selection from a list of current tags Documentation update, including information about using pb_tool to compile, deploy, and package your plugin New URLs for Plugin Builder’s home page and bug tracking Optional is now Recommended In previous versions the following items were “Optional” when creating a new plugin:
Matthew Perry poses the question: Why is the command line a dying art?. Funny how these things go–I was thinking about posting on this same topic just the other day, although I may be repeating myself. The efficiencies of the command line cannot be overstated. I too have seen that deer in the headlights look when a GUI-only user is first exposed to a command prompt. I have also seen people spend days on a data conversion project that could easily be accomplished in hours (or less).
The death of the shapefile has again been predicted—this time for 2010. The technical description of the format has been around for going on 12 years. In that time it has become a sort of lowest common denominator for data exchange. They’re everywhere. Making them go away is going to require a revolution of sorts. ESRI has been sounding the death knell for the shapefile for a while now. I agree that it isn’t a perfect format but it is nearly perfectly supported.
When writing plugins or scripts it is often necessary to get information about the paths QGIS is using. For example, if we are writing a plugin that uses Python templates to create output based on user actions, we need to know the path to our installed plugin so we can find the templates. Fortunately the API provides an easy way to get at the information; here are a few examples:
If you’re a developer, or have looked at the QGIS source code, you’ve likely noticed that most C++ classes in the project start with Qgs. Back before the dark ages of QGIS, Trolltech (now Digia) allowed you to reserve name prefixes for classes that used the Qt framework. Shortly afterwards, I reserved the gs prefix for my use, resulting in class names that start with Qgs. You might think this is based on some mangling of words like QGIS or perhaps GIS, but it was purely egocentric:
At the ESRI Developer Summit there was news of the File Geodatabase (FGDB) API. Based on the tweets from the summit it appears: The API will be C++ only API works on Windows and Unix/Linux (specifically RedHat, Solaris, SuSE) operating systems Rudimentary support only—features such as annotation, relationships, topologies, etc. are lacking Since ESRI is releasing a targeted API and a not a specification, support for Mac OS X is out of the question.
Well it was a short summer here. Or perhaps we have defeated global warming. This is the view from the deck on Thursday evening: and this is the view Saturday morning: Of course nearly everyone in the country has removed their snow tires in anticipation of the upcoming May 1 deadline. As they say “Life is tough in the far north”. The good news is that now we can go directly from winter to summer…
QgisToMapServer converts a saved QGIS project file to a map file, ready to be served with MapServer. A binary preview version for both Mac and Windows is available now. For Linux/Unix users, the source code is available from the Git repository. QgisToMapServer is different from the plugin in QGIS. It is a standalone Python application providing the following features: Create MapServer map files from saved QGIS project files
The MapServer Technical Steering Committee today approved an RFC that calls for MapServer to join the newly formed Open Source Geospatial Foundation. A poll has been put up on the MapServer site (login required) to collect the responses from the community. So far the vote is unanimously in favor of joining, although the poll has only been open for about an hour. Some thought it interesting that MapServer didn’t join immediately, given it was at the center of the failed MapServer Foundation attempt at the end of last year.
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, they must be loaded in QGIS.
The forum (http://forum.qgis.org) has been closed for new registrations and marked read-only. Users have been encouraged to use http://gis.stackexchange.com instead. If you have an thoughts on the closure, good, bad, or otherwise, please comment.
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 method has a couple of advantages, at the expense of a bit of disk space: Quicker compiles compared to branch switching, especially if you are using ccache Less likelihood of making a merge mess when switching branches The basic steps are:
If you use Vim you probably know you can use the make command to build your project. The make command looks for a Makefile in your current directory. If you are editing a file that is not in the current directory (meaning you use some Vim magic to change to the directory containing your edit buffer), make will start below the top-level of your build directory. This is often the case when doing an out-of-source build with CMake.
