december 2006 archives

Thursday, December 28, 2006

Beyond red dot fever

If online mapping has taught us one thing this year: red dot fever is contagious. Everyone's putting pins on maps, virtually of course. Whereas it seemed to be contained to the US earlier this year, the first break-out in Europe started in April and was later followed by a second wave in November. Dutch cases of red dot fever are registered at Nederkaart.

Little by little, people are recuperating. Treinvizier deservedly became second in the Ben jij beter dan Microsoft? contest for mashups. Treinvizier doesn't just put icons on a map, but it animates the icons to simulate the movement of trains across the Netherlands (even allowing for delays): the poor man's Google Transit.

Thematic mapping — not to be confused with themed mapping — also provides a cure against red dot fever. gCensus (currently down for an overhaul so check these images) took a first stab at presenting US Census 2000 overlaid on Google Maps, but it didn't cure the red dot fever. Metroview provides interactive viewing of statistical data per MSA using Google Maps and shows the first signs that mapping statistics is a cure: Metroview shows the boundaries of the enumeration areas. These boundaries are inserted as an XML overlay created from ESRI shape files, generated with proprietary conversion software. Despite the note that large polygon files may cause significant performance degradation, Metroview takes a long time loading in your browser and may even produce a JavaScript error pop-up Stop running the script?.

Webfoot Maps and Neighboroo have shaken off the red dot fever completely. Webfoot Maps is another Census/Google Maps mashup, but adds a custom map type of 256*256 raster tiles instead. The custom map is a choropleth map: the darker the red, the higher the value for an enumeration area. Neighboroo covers topics from socio-economic trends, environmental issues to real estate. Just like Webfoot Maps, Neighboroo uses custom map types of raster tiles, but pulls the data from various sources. While Webfoot Maps makes use of a tile-server script to generate the tiles, Neighboroo stores the tiles as flat images in their web folder. The Neighboroo custom maps are choropleth maps using a diverging red/green colour scheme. To account for red/green colour-blind visitors, all maps can also be shown using a yellow/blue colour scheme.

Admittedly, these examples all build on the Google Maps API. I would love to see similar examples on the Yahoo Maps Gallery or even OpenLayers Gallery. Any suggestions welcome.  permanent link for this entry