[QGIS-trac] Re: [Quantum GIS] #1969: Area tool goes amok

[Quantum GIS]

#1969: Area tool goes amok
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        Reporter:  vince                             |         Owner:  homann           
            Type:  bug                               |        Status:  new              
        Priority:  major: does not work as expected  |     Milestone:  Version 1.4.0    
       Component:  Projection Support                |       Version:  1.3.0            
      Resolution:                                    |      Keywords:  area tool measure
Platform_version:  10.6 (Snow Leopard)               |      Platform:  All              
        Must_fix:  No                                |   Status_info:  0                
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Changes (by lutra):

  * owner:  nobody => homann
  * platform:  OS X => All
  * component:  Vectors => Projection Support

Comment:

 Replying to [comment:8 vince]:
 > The bug affects the linear ruler too. It seems to be triggered by the
 'on the fly' projection conversion option.


 can you be more specific (maybe posting a sample of your data)?

 This is my observation:

 - open a new project and check in the options that the "preferred
 measurement unit" is meters and that otfr is disabled

 - add a layer with a projected CRS: if the "layer unit" option (in the
 "general" tab of the "project properties" menu) is defined accordingly
 with the layer CRS unit, then all "measure area", "measure line" and
 scalebar do give *right values*

 - if by mistake you have a layer with a CRS unit defined in meters BUT the
 "layer unit" defined in feet or degrees, you'll read wrong values despite
 having "preferred measurement unit" in meters.


 Lewt me know if this make sense to you.

-- 
Ticket URL: <https://trac.osgeo.org/qgis/ticket/1969#comment:9>
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