Here I post my thoughts, QGIS tips and tricks, updates on my QGIS-related work, etc.
09.08.2012 11:57 · Notes, Site · blog
Yesterday this blog turned 5 years old. After that time, I can say that the idea of blogging was not that stupid. And even though I don’t write regularly and it’s more for myself, maybe some of the posts have been useful or just interesting to readers.
I don’t know how many readers I have, but thank you for sticking with me.
09.08.2012 11:33 · GIS · qgis, ftools, processing
Reviewed 19 fTools tools in two groups: cleaned up the code, fixed some bugs, optimised a bit. There is still as much to do. Then test and if no critical bugs appear, I will commit.
01.08.2012 14:23 · GIS · qgis, ftools, processing
SEXTANTE will soon become part of QGIS: the code freeze in the old repository and the migration are scheduled for 20th August. After the migration, only the Java-related part will remain in the old repository, while QGIS will get a new core plugin.
In this context, I have decided to revise the fTools provider code, synchronise it with the original utilities, and generally prepare for migration and code removal in any way possible. I will be happy if someone helps with testing and is willing to publish plugin package with the latest fixes.
25.07.2012 17:12 · GIS, Notes · qgis, processing
Four patches + an elegant solution to a problem, and… I became a full member of the development team of the SEXTANTE project.
20.07.2012 19:09 · GIS · qgis, plugins
One type of data used in GIS is geotagged photos, i.e., photos whose metadata includes the coordinates of the location where the photo was taken. But there are not many tools for working with such photos in QGIS: all that comes to mind are eVis, photo2shape and its little-known ideological parent, ImagesToShape. In principle, these two modules are sufficient for many tasks. You can use photo2shape to map the locations of photos and use eVis to view geotagged photos and link them or other documents to features of a vector layer. Sooner or later, however, a task will arise for which the capabilities of the existing tools are not sufficient.
Geotag and Import Photos is a new QGIS plugin developed for NaturalGIS. It allows you to process geotagged photos, geotag them and create a point shapefile from them.
Key features:
Today, 19 July, Quantum GIS celebrates its 10th birthday. Over the years, QGIS has grown from a simple PostGIS data viewer developed by one person to a full-featured, extensible, cross-platform desktop GIS with support for multiple data formats, extensive analysis and design capabilities, which is developed by programmers from around the world and used successfully by individuals and organisations.
I suggest we remember how it all started.
Read more ››29.06.2012 18:35 · GIS · qgis, plugins, processing
There is a software called TauDEM (Terrain Analysis Using Digital Elevation Models). It provides a free (GNU GPL v2) set of tools for extracting and analysing hydrological information from digital elevation models. TauDEM is developed by David Tarboton of the Water Research Laboratory at Utah State University.
The tools are written in C++, are cross-platform, and have a console interface. Users of ArcGIS 9.3.1 and 10.0 can install an add-on that allows them to run the tools from ArcToolbox using simple dialogs. For others, the only way to use TauDEM is the “scary” command line.
Recently, QGIS also got a powerful and convenient framework that allows easy integration of various tools and libraries (yes, I’m talking about SEXTANTE). Thanks to this framework, QGIS users who need hydrology tools now have a way to use TauDEM directly from QGIS.
Of course, you need to have TauDEM installed in order to use the plugin. While the installation on Windows is quite simple (there are compiled files and detailed installation instructions on the site), Linux users will have to build TauDEM themselves.
Read more ››21.06.2012 09:29 · GIS · qgis, release
Almost a year has passed since the release of QGIS 1.7.0 “Wrocław”. It was supposed to be the last release of the 1.x branch, but time has taken its toll. The developers simply do not have enough resources to maintain several branches simultaneously, so it was decided to abandon the division into “stable” and “development” branches. All future releases will be based on the master branch. The result of these revised plans is the release of QGIS 1.8.0 “Lisboa” today.
This release contains many bug fixes and a significant number of new features. In addition, QGIS 1.8.0 has some minor API changes that affect the print composer. If you are using this part of the API in your plugin and are experiencing problems, the developers will be happy to help you adapt your code.
You can find a detailed description of the new features in the official announcement. I will only mention the most interesting ones:
20.06.2012 18:56 · Notes · thoughts
Inspired by some forum topics and the general attitude of some users (observed in IRC, bugtracker, mailing lists and personal emails). I actually wrote a bit about this a few months ago. One more time and that’s it, I won’t go back to it.
The random user is perplexed and outraged because the developers refuse to implement the feature (which gradually becomes a set of loosely connected features) that the user needs for his specific task. Really, why? First of all, the requested functionality looks strange not only to the developers, but also to many other users who, by the way, have a certain weight and influence in the community (more on this below). This means that the importance and necessity of the requested functionality are highly questionable. The second point that the user persistently ignores is the existence of a third-party plugin that does virtually everything they need. It is enough to make a minimal modification to the plugin yourself or to contact the author (an adequate and responsive person who responds promptly to comments and polite, reasoned requests).
The software is made for everyone, there is a roadmap and a vision for future development. And it makes no sense to add something to the core that only a single user needs, especially if there is a plugin with similar functionality. If the feature is really important and should be in the core — justify it. Developers cannot physically know and foresee everything, so if you can explain to them why it should be this way and not that way, changes will be made. After all, they want the program to be convenient and useful. Just remember that reasons along the lines of “I use your software in my company, so you have to…” look silly as an argument.
Another user complains that developers “resist when bugs are clearly pointed out to them”. Obviously, resistance should be understood as a polite request to describe the nature of the problem and the proposed solution in more detail. By the way, it is at least not nice to reply to a stranger with “wise will understand”. It may well turn out that this person is much wiser than you are.
It’s not unreasonable to repeat a few very simple things here:
Also don’t resent the fact that some bugs are fixed when
the problem will “hit” one of the developers or people who have influence over them
It’s expected and normal. Let me try to explain why this happens.
The reason people get into development is almost always the same: they need a convenient tool to solve their problems. As a result, people first work on what they need/are interested in. In other words, people make software for themselves. It is logical that the bugs that hinder the developer personally will be fixed first. The same goes for adding new features.
Furthermore, in any relatively large project, each developer has their own area of responsibility. Some developers are responsible for one subsystem, others for two or three. And no one is going to dive into someone else’s code without a real need: it takes time. And as I have already mentioned, developers tend to be enthusiasts and spend their own free time on it. Do you think there will be many people willing to dig into someone else’s code, with a vague description of the problem and no way to reproduce the bug, instead of doing something more interesting?
Now about “people who have influence over them”. Usually, these are not just some abstract John or Jane. Developers are influenced by people who are recognised in a field, who have knowledge and authority, and who are doing something useful. Both recognition and influence do not just appear, they are well-earned. These people have already proven that their opinions count for something; they not only take from the community but also support it (not necessarily financially, though it can be financial support too). Of course, we shouldn’t ignore the factor of personal sympathy: I don’t think anyone would argue that people are more likely to help their friends than complete strangers.
All of the above applies to “volunteer-based” development. If you are not satisfied with such an arrangement — find your own way to motivate people. When the canton of Solothurn needed annotations, they didn’t moan “Do it for us, we use QGIS”. Instead, they approached Marco, described the problem, got him interested, and soon got what they wanted. When Andreas finds a bug, he reports it with a detailed description and a test dataset. In urgent cases, he always finds a developer willing to help solve the problem. And these are not isolated examples.
Perhaps you should reconsider your attitude to opensource?
30.05.2012 18:51 · GIS · qgis, howto
Recently, there have been a lot of questions about working with CSV files in QGIS. So here is my attempt to shed some light on this complex and confusing topic. Be prepared for a longread.
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