The OpenStreetMap movement has a great trick up their sleeve for manipulating their data – osmosis. It’s the sort of tool that map, GIS and navigation companies probably have developed in-house, only I’m prepared to bet that this one’s more elegant than most of theirs. For straightforward tasks such as loading some OSM data into Postgres the documentation was clear to me. However, I have been scratching my head more than somewhat with the more subtle plumbing. Continue reading “Plumbing With OpenStreetMap osmosis”
Git and Subversion are the flavour of the month for source control time machines. I’ve used just about every source control system that’s been made over the years including RCS, PVCS, SourceSafe, ClearCase, Perforce and CVS. There’s a nice history of version control systems here. Here’s my cheat sheet (for Linux / OSX / Cygwin) users. Continue reading “Git and Subversion Cheat Sheet”
Ubuntu 12.04 is here and I’ve been using it for almost a month now. It’s the Long Term Support version so it’s going to be around for many years to come. Also Canonical, the company behind Ubuntu, is doing a fantastic job of getting Ubuntu pre-installed on PC’s in favour of Windows. However, there are some significant changes to the UI that Ubuntu has introduced in the past year or so that take some getting used to. Here are some tips to get the most out of this latest version with the minimum sweat. Continue reading “Ubuntu 12.04 Top Tweaks”
It’s Java so you don’t need to worry – the garbage collector ‘just does it’, right?
java.lang.OutOfMemoryError: Bitmap Size Exceeds VM Budget is a common error and don’t we know it! The garbage collector isn’t totally magic and no guarantee that your app cannot / will not leak memory. There are various deliberate approaches / considerations that should be taken to avoid memory problems: Continue reading “Avoid Out-Of-Memory Problems in Android”
If you want to manage a custom schema with a web interface with multiple users, multiple languages for UI and content, you could roll your own using something like CakePHP to provide a framework. Doing it that way, you’ll be re-inventing many wheels for user management, authentication, etc. I evaluated half a dozen ‘higher-level’ CMS and settled on Drupal since it has all of this infrastructure plus many mature add-ons (‘modules’) that mean that you can focus on implementing the specifics of your web application rather than writing lots of plumbing. Furthermore, it’s PHP so it’s easy to deploy on inexpensive hosted services on the internet (not something that you can say for Java-based CMS, for example). Continue reading “Georeferenced Rich Content Management with Drupal 7”
A friend forgot their admin password to their Windows machine (as it happens it was Vista). A great, free open source Linux-based utility made it frighteningly easy to clear / reset the password. Job done in 5 minutes. So, thanks Petter, your ntpasswd utility rocks. And free, open source software based on Linux saves a Windows user’s bacon – oh, how sweet that sounds. While I was at it I installed Ubuntu 11.10 on an old laptop of theirs. Needless to say, they were wowed that it boots and shuts down like greased lightning, has lots of (legally) free apps to download / manage from a single control and ‘does all the same things as Windows’ (but better, as they will come to believe, bwahahahaha).
Currently there is no pointy, clicky way to change a field’s machine name once you’ve created it. With due credit to a blog post here I present a very simple script to create the SQL necessary to make the changes to the field name using PostgreSQL. Continue reading “Renaming Field Names in Drupal 7 + PostgreSQL”
Not every map data set you come across is WGS84, unfortunately. For example, I just needed to mix some IGN Spain data (in ETRS89) with some OpenStreetMap data (which was in WGS84). Here’s a quick fix. Continue reading “Use PostGIS to Transform Map Data Projection”
I’ve seen a few recipes on the web but none worked for me on Ubuntu Oneiric. Here’s what I did. Continue reading “Install PostgreSQL 9.1 and PostGIS 1.5.x on Ubuntu 11.10”
I’ve been using Linux as daily as a server and workstation since I first installed SLS from a pile of floppies back in ~1993. Since using Ubuntu for a long while I’ve become used to the UI, and so this is my quick to-do list for workstations and servers to be set up on my intranet with Ubuntu 11.10. Continue reading “Top 10 Tweaks to Ubuntu 11.10 For Old Ubuntu Hands”