Friday 23 September 2011

"Vectors are your friend"

HTML5 Canvas was a natural extension for  Its distinction is to post vectors on the web, overlaying rasters like any GIS, and with a optional postGIS running in the background. Not only does this speed up drawing maps on the web, it also allows massive amounts - in the millions of points, lines and polygons - to render PDQ (pretty darn quickly) - thus Vectors are your friend - my moderately complex maps benefit from even clean&crisper renderings of polygons as expected and of tiled images especially.

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This is my old Medieval Fenlands map in East Anglia with 10 layers at 2000 polygons each and two web mapping services - zoom in an out to appreciate its speed.

Here's NOAA's Global Self-consistent, Hierarchical, High-resolution Geography Database, as well as USGS earthquake and plate boundary map - not insignificant vector maps that zoon in&out quickly... try it out!

@giscloud is still new so there is a way to go yet - as some of the tweets that increased 1500% in the last few days indicate - labelling, scale dependency, layers and legends, etc. Note also that as this relies on HTML5: pre-rel. 9 Internet Explorer that don't support it will automatically revert maps to their original rendition.

Fifteen years ago Argus' distinction from ArcView and Mapinfo was to render in less than 5 s. all 50 US states and 3000+ county polygons. And about that time Hipparchus claimed to map the solar system at metric scale... One could say that:
What goes around, goes around, goes around again,
da-na-na da-na-na da-na-na my friend say
Where you gonna run to? When it gonna end?

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