[QGIS-trac] Re: [Quantum GIS] #2906: Scaling of values used in "Area scale" (or "Size scale field")

[Quantum GIS]

#2906: Scaling of values used in "Area scale" (or "Size scale field")
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   Reporter:  nikos                                                        |              Owner:  nobody       
       Type:  enhancement                                                  |             Status:  new          
   Priority:  minor: annoyance                                             |          Milestone:  Version 1.6.0
  Component:  Symbology                                                    |            Version:               
   Keywords:  points, symbols, area scale, size scale field, scale factor  |   Platform_version:               
   Platform:  All                                                          |           Must_fix:  No           
Status_info:  0                                                            |  
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Comment(by nikos):

 Replying to [comment:1 lutra]:
 > The field "size" should already work as scale factor. This it at least
 how it works in qgis trunk/1.5. Please give it a try.

 Thank you lutra. I already (and usually) work with "trunk". The "size"
 field affects all points which is not what I want. Perhaps I did not
 explain my wish clear enough. So another example:

 1. I choose one svg-based symbol (e.g.[1])[[BR]]
 2. set the size to e.g. 7[[BR]]
 3. I choose the "aspect" column (values in degrees) to rotate the arrow
 symbol according to the aspect (works perfect)[[BR]]
 4. further, I want to size each of the symbols separately and
 proportionally-to/based-on let's say elevation values! [[BR]]

 To make a bit complicate (and give an idea about what I would like to have
 as a scaling factor option), I would like that higher elevation values
 would make the symbols to appear smaller and, the opposite, lower
 elevation values should make the symbols to appear bigger.[[BR]]
 So, given that I have an elevation column it takes me to figure out how to
 transform the existing values, create a new column, update it, set this
 new column in the "Area scale" (or "size scale field" in the new symbology
 dialog).[[BR]]

 Of course the simple version is to have the option to scale down for
 example area size values (varying from a few square meters up to some
 hundred square meters). So I could on-the-fly turn 1000 to 10 and 100 to
 1.

 Not that I expect a magic do-it-all tool, but the ability to
 manually/arbitrarily(?) scale further the values stored in a column (of an
 attribute table) would be great.

 Hopefully I explained it well (this time). Thank you, Nikos
 ---[[BR]]
 [1]
 [https://trac.osgeo.org/qgis/browser/trunk/qgis/images/north_arrows/NorthArrow_blackyellowblack.svg?rev=13955]

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Ticket URL: <http://trac.osgeo.org/qgis/ticket/2906#comment:2>
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