[GRASS-dev] [GRASS GIS] #547: Raster query in wxGUI

GRASS GIS trac at osgeo.org
Mon Apr 6 09:16:12 EDT 2009


#547: Raster query in wxGUI
---------------------------+------------------------------------------------
 Reporter:  hcho           |       Owner:  grass-dev at lists.osgeo.org
     Type:  defect         |      Status:  new                      
 Priority:  major          |   Milestone:  6.4.0                    
Component:  wxGUI          |     Version:  svn-trunk                
 Keywords:  raster, query  |    Platform:  Linux                    
      Cpu:  x86-32         |  
---------------------------+------------------------------------------------
 GRASS_REGION is set to the current display settings before raster queries
 in gui/wxpython/gui_modules/mapdisp.py line 1117. However, the only
 changes r.what can see are nsres, ewres, nrows, and ncols. East, west,
 north, and south remain unchanged even after zooming/panning. Any ideas?

 WxGUI uses the display region/resolution for raster query (compReg=False
 in line 1152). Setting aside the above issue, why can't we just use the
 computational region for raster queries? Differences between the
 computational and display regions cause a cell-alignment problem where the
 user gets several different values within a single cell. For example, if I
 click eastern part of a cell, I get the correct value. But, if I click
 western part of the cell, I get the value of the left-adjacent cell. When
 I removed the compReg=False option, this problem disappeared.

 R.what already takes care of everything related to query in the
 computational region, and what we need to pass to it is just a map name
 and coordinates. I don't see the need for GRASS_REGION and compReg=False.
 Am I missing something?

 Thanks.

-- 
Ticket URL: <http://trac.osgeo.org/grass/ticket/547>
GRASS GIS <http://grass.osgeo.org>


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