[QGIS-trac] Re: [Quantum GIS] #1497: colormap edge case handling wrong for negative valued rasters

[Quantum GIS]

#1497: colormap edge case handling wrong for negative valued rasters
-----------------------------------------------------+----------------------
        Reporter:  Barryrowlingson                   |         Owner:  ersts        
            Type:  bug                               |        Status:  assigned     
        Priority:  major: does not work as expected  |     Milestone:  Version 1.0.2
       Component:  Rasters                           |       Version:  HEAD         
      Resolution:                                    |      Keywords:               
Platform_version:                                    |      Platform:  Linux        
        Must_fix:  No                                |   Status_info:  0            
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Comment (by Barryrowlingson):

 Here's two 3x2 esri grid files - one exhibits the problem, the other
 doesn't:


 {{{
 NCOLS 3
 NROWS 2
 CELLSIZE 0.9125
 XLLCORNER 12.15
 YLLCORNER -5.81
 NODATA_value  -26
 -2.66226 -2.720158 -3.119102
 -1.747691 -1.321416 -1.096483

 NCOLS 3
 NROWS 2
 CELLSIZE 0.9125
 XLLCORNER 12.15
 YLLCORNER -5.81
 NODATA_value  -26
 -2.66226 -2.720158 -3.119102
 -1.747691 -1.321416 -1.196483
 }}}


  the only difference between them is I've changed the max value from
 -1.096483 to -1.196483.

 For the first grid, that cell shows up as white, for the second grid it is
 coloured okay.

 Recap: load grid, Properties, set 'Colormap' mode, on colormap tab choose
 4 entries, classify, apply.

  This is on 1.0.0 Kore release - I've not got a build environment up at
 the moment. If all this has changed a lot in HEAD then maybe it's all
 fixed. I might try and sort out building later.

 thx for looking into this.

-- 
Ticket URL: <https://trac.osgeo.org/qgis/ticket/1497#comment:3>
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