[Qgis-user] proportional symbols

[Barend Kobben]

Proportional point symbols indeed ARE one of the most important cartographic
map types. If this gets implemented well in QGIS I am all for it. But please
take care to do it right then! One important thing to note:
For most symbols (2d symbols like squares and circles, ect) it's NOT 'double
population should mean double SIZE', its actually 'double population should
mean double AREA of the symbol'. Ie.  1x1 mm square = 10 people , 10x10 mm
square = 1000 people.

I've attached some slides from a lecture I regularly give about that. If
needed, I can provide further advise or additional references...
[attachement was refused, I've put it on:
http://kartoweb.itc.nl/fileshare/propPointSymbols.pdf
] 

yours

-- 
Barend Köbben
International Institute for Geo-Information
Sciences and Earth Observation (ITC)
PO Box 6, 7500AA Enschede, The Netherlands
+31 (0)53 4874253


> 
> It seems to be a more common feature than I thought. Still I don't
> understand the use if this (I think double size should mean double
> population) but I guess I can live with the clutter.
> 
> Goyo

International Institute for Geo-Information Science and Earth Observation (ITC)
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