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Offline copy of GIS project data files!

I was glad to read about this “Offline Editing Plugin for QGIS”. For many working in enterprise environments, the idea of handling a disk full of separate files is a nightmare (or a nightmare waiting to manifest if it hasn’t already), particularly in a mobile collection scenario. So being able to have an app download data from database sources and sync them back online later has the potential to really help manage spatial data.


“For data collection, it is a common situation to work with a laptop or a phone offline in the field. Upon returning to the network, the changes need to be synchronized with the master data source, e.g. a PostGIS database. If several persons are working simultaneously on the same datasets, it is difficult to merge the edits by hand, even if people don’t change the same features.

Therefore, Mathias Walker implemented an offline plugin for QGIS. This plugin automates the synchronisation by copying the content of a datasource (usually PostGIS or WFS-T) to a spatialite database and storing the offline edits to dedicated tables. After being connected to the network again, it is possible to apply the offline edits to the master dataset.”

Links and instructions from the full article page. Guess I’ll have to get back to building QGIS from sources to try it out, at least until it’s rolled into a repository or core feature set.


QGIS and Spatialite – it just works

I gave SQLite, or is that spatialite, support in QGIS a try tonight. Surprise – it just works out of the box it seems. I know it may have worked in previous version too, but only now I just got around to testing it.

I downloaded a sample spatialite db, downloaded the latest QGIS (1.5.0-2 for Snow Leopard) from Kyngchaos. Unzipped the spatialite db, added it as a layer datasource, choose the three layers that appeared in the list. Voila.

Then I edited the file, added a point and saved it. Just to be sure I removed the layer and re-added it and my new point was still there. Lots more fun ahead for this great little “single file” datasource. Bye bye shapefiles… someday.

Installing Maemo 5 SDK

I’m looking into understanding the Maemo 5 platform with the hopes of building some OSGeo applications for it in my spare time. So, yes, that likely means I won’t get far!

Here is my first hour’s progress getting this started on install the SDK on my Sidux Debian box.
These SDK install notes from are leading me.

  • Ensure the xserver-xephyr (debian) package is installed on my workstation.
  • Download installation application (python script), chmod a+x, then launch it via sudo. (screenshot)
  • Go through wizard, select standard installation, accept license… (screenshot,screenshot)
  • Not sure what this VDSO settings for scratchbox are all about, so will simply continue and check I Accept (screenshot)
  • Choosing defaults for installing Nokia apps, etc. Scroll down license agreement and enter the number code shown. Click Accept. (screenshot) Shows summary of installation, press install.
  • Several downloads begin.

Installer ran fine for about 15 minutes then stopped with message “Failed: 4/9 Installing SDK Targets” (screenshot) the log says to run sb-menu once before continuing. Not sure if the installer did that without me seeing, but I tried to run it manually. (sudo sb-menu) that failed the same way though. The wizard forces you to finish which really means give up 🙂

Rooting around in searches online I found someone with same trouble ran this: sudo sysctl abi.vsyscall32=0. Gee, hope that doesn’t break anything else on my system 🙂

  • Restarting installation picks up with “upgrading scratchbox” and continues well! (screenshot)
  • Noticed a few mime related error flying by a couple times.
  • After about 20 minutes it finished up successfully (screenshot), giving a few notes for what to do next. (screenshot)

Autodesk’s Revit, Butterfly and Google Maps

Usually I’m 100% focused on open source software, but couldn’t resist talking about this side project. A couple months ago Geoff pointed out the new Autodesk Butterfly project, allowing you to share and collaborate on drawings using only a web browser. They have some geospatial examples on there too. Here are couple notes about my tests on it lately.

More recently, in my spare time I’ve been learning the Autodesk Revit Architecture software, so was keen to try it out along with the latest Butterfly geospatial features – georeferencing to a Google Map background. It worked well for me and a tutorial drawing I worked on last night. Their latest blog post even mentions support for GDAL data formats used as backgrounds in the drawings (go GDAL!).

Why am I interested in any of this? The past several months I’ve been trying out various packages for doing architectural design. I’ve taken time to try out several general packages and a couple more building specific ones. Most notably, Blender 3D (open source), Sketchup (free) and most recently Revit (cost).

Albeit the most expensive of the three, in only a couple days, Revit’s 30 day trial had me up and running with some really cool features and ease of use. I’ve barely scratched the surface but I’m able to build pretty smart models, way more than just drawing lines and doing pretty rendering. So, when I learned about Butterfly and now had some DWG files to try out on it, I couldn’t resist.

I hope to dig into converting some DEM data into Revit’s topography format at some point as well. I also hope to see Butterfly supporting loading large rasters directly – at the moment they have to be include inside your drawing files.

What book do you need?

(ED: Enabling comments might help.. sorry about that, should work now. TM)

I talk a fair bit with various folks about book ideas they or I have. I’m curious on your thoughts for potential new books that might be popular – what’s the next big “geo” book that you think you, your colleagues, the world at large needs?

Where do these books leave off? Or what new waters need to be charted?

MapServer Workshop at FOSS4G 2010

Hope to see you at the MapServer introduction workshop at FOSS4G 2010 in Barcelona this September.

As usual, it’s a team teaching approach for beginners, delivered by Jeff McKenna, Perry Nacionales and myself.

This workshop always sells out and people beg to join in or stand at the back – so sign up soon or you might miss out.

See you there!

Install Skype on AMD64 Debian/Sidux

I switched to running the Sidux distribution not too long ago, at the same time I upgraded to a 64 bit AMD machine. It’s my first foray into Debian based distros and has been pretty nice until I went to install Skype. I won’t regurgitate the other message boards, but in a nutshell here was my solution:

  • Add Medibuntu repository to my apt sources. I had to manually select the hardy.list file to download since there were no sid.list files.
  • Install ia32-libs and ia32-libs-gtk packages via apt. May need other ia32-libs-* as well.
  • Update apt and install Skype package via apt. NOT by downloading from Skype website

I use Pidgin IM with a Skype plugin package, so I have a single contacts list. Bummer is I have to have Skype running in the background so it can communicate via dbus, but it’s better than nothing.

Meet me in Sydney

The biggest annual event for me and OSGeo is fast approaching. The FOSS4G conference event, held this year in Sydney, Australia, will be held in October. I’d love to meet you there if you would like to chat about open source, GIS, cartography, programming and all such related topics. Attend a workshop to learn to make maps or run web mapping sites. Or just come to hear talks from leaders in the open source geospatial community.

You’ll find friends from all programming language communities there showing you how they get things done. From government to industry to NGO and the hobbyist users – all will find content that is appealing and useful.

Open source geospatial toolkits are used behind many of the largest GIS software packages and web mapping sites. Learning these tools helps build your own personal set of tools for doing the job well.

Hope to see you there!


Open Source Car Needs Open Source Navigation

I recently came across the project – a forum to develop energy-efficient cars using an open source approach.

While waiting for more information from them, I did some thinking about what parts of this kind of project would interest me or how OSGeo or other geospatial projects could help them out.

Perhaps someone out there has already though about Open Source navigation project using OSGeo tools. If so, I’d encourage you to contact them.

It’s also interesting to me to consider how embedded hardware could work in these vehicles. Imagine having an open API and open connectors to access data in the machine. Starts to sounds pretty interesting to me.