[QGIS-trac] Re: [Quantum GIS] #960: Area scale field: make standardized symbol dimension and legend

[Quantum GIS]

#960: Area scale field: make standardized symbol dimension and legend
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        Reporter:  giohappy          |         Owner:  homann                            
            Type:  enhancement       |        Status:  closed                            
        Priority:  minor: annoyance  |     Milestone:  Version 1.6.0                     
       Component:  Symbology         |       Version:  HEAD                              
      Resolution:  wontfix           |      Keywords:  area scale field, graduated points
Platform_version:                    |      Platform:  All                               
        Must_fix:  No                |   Status_info:  1                                 
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Changes (by jrm):

  * milestone:  => Version 1.6.0


Comment:

 Biased proportional symbol are possible in most GIS software, here a few
 methods :

 [http://www.geog.ucsb.edu/~jeff/gis/proportional_symbols.html#gradsym /
 ArcGIS] -> use a size range (e.g. lowest is at 4pt and the biggest at
 22pt) or use Flannery's compensation

 [http://www.kxcad.net/MapInfo/MapInfo_Professional/MapInfow-19-11.html /
 MapInfo] -> use a size range (you can determine the interpolated symbol
 size using the square root, a constant or a log)

 [https://confluence.prodevelop.es/download/attachments/10911941/symbol-
 proportional-config-
 background.png&imgrefurl=https://confluence.prodevelop.es/pages/viewpage.action%3FpageId%3D10911941&usg=__fd_jfT6xJkCFCc5ahU0EETQKe-0=&h=470&w=720&sz=23&hl=fr&start=8&um=1&itbs=1&tbnid=D_RYTyWJpd3W7M:&tbnh=91&tbnw=140&prev=/images%3Fq%3Dproportionnal%2Bsymbol%2Bgvsig%26um%3D1%26hl%3Dfr%26client%3Dfirefox-a%26sa%3DN%26rls%3Dcom.mandriva
 :en-US:unofficial%26tbs%3Disch:1 / GvSIG] -> use a size range

 [http://demo.mapfish.org/mapfishsample/1.2/examples/geostat/proportionalSymbols.html
 / MapFish] -> use a size range

 Some good read on the subject :
 [http://makingmaps.net/2007/08/28/perceptual-scaling-of-map-symbols/ /
 Perceptual Scaling of Map Symbols]

 Daniel R. Montello, Cognitive Map-Design Research in the 20th Century:
 Theoretical and Empirical Approaches
 [http://www.geography.wisc.edu/histcart/v6initiative/12montello.pdf / PDF]

 James Flannery, The Graduated Circle: A Description, Analysis, and
 Evaluation of a Quantitative Map Symbol

 Susumu Tanimura and al., Proportional Symbol Mapping in R
 [http://www.jstatsoft.org/v15/i05/paper / PDF]

 Bernhard Jenny, Self-Adjusting Legends for Proportional Symbol Maps
 [http://jenny.cartography.ch/pdf/2009_Jenny_Legends.pdf / PDF]
 [http://jenny.cartography.ch/legend/ / Exemples]

 Original [http://lists.osgeo.org/pipermail/qgis-
 developer/2010-June/010301.html / post] on qgis-dev's ml

 Making it possible to show the size in the legend would be a small step
 that would still be compliant with Tufte's rigorous ideas.

-- 
Ticket URL: <https://trac.osgeo.org/qgis/ticket/960#comment:12>
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