OS and GM SXS for LEJOG in the UK

Translation: Ordnance Survey and Google Maps side-by-side for planning the Land's End-John O'Groats walk in the United Kingdom.

My friend Steve is walking the LEJOG in 2010 (I guess that makes him a LEJOGger - as opposed to the JOGLErs who go North to South). Of course he is blogging about it - doesn't everybody?.

Even better, he's planning his route using Where's The Path, which is a fantastic side-by-side map site for the U.K. It shows Ordnance Survey topographic maps and Google Maps imagery in a cleverly linked view (similar to the VExGM web site I blogged about earlier this year, but even more useful). Here's a link to the most famous location in Britain (but I suspect it doesn't feature in many LEJOG itineraries, unless you're a real anorak for walking).


WTP also lets you digitize paths and export them to GPX and KML. Steve is finding the KML export particularly useful, since it allows him to locate all the pubs along the route of his walk.

Now, when is someone going to do this for Canada? All those prospective SJV'ers out there would be overjoyed!

KML Pie Charts in JEQL

Pie Charts are a nice way of displaying thematic visualization in Google Earth. They're also a good test of the chops of a KML generator. So naturally I was keen to see how to produce pie charts with JEQL.

For simplicity I decided to make my test statistic an orthographic comparison of the names of countries, showing the relative length of the country names and their vowel/consonant distribution. (This wasn't because this is a particularly interesting statistic, but it uses easily available data and exercises some of the data processing capabilities of JEQL).

The solution ended up using lots of existing capabilities, such as splitting multigeometries, regular expressions, JTS functions such as interior point, boundary and distance, and of course generating KML with extrusions and styling. The only new function I had to add was one to generate elliptical arc polygons - which is a good thing to have.

The results look pretty snazzy, I think - and would be even better with more meaningful data!

KML Craziness

Why oh why did KML choose to specify colour values as AGBR ABGR rather than RGBA? Does anyone have a rational explanation for this anomaly?