Opened 13 years ago

Closed 13 years ago

#40 closed defect (fixed)

strange values for GRASS raster data in QGIS

Reported by: alesarrett Owned by: jef
Priority: major Component: Package
Version: Keywords:
Cc: warmerdam

Description

GRASS raster with real data (for integer it's all ok) have problems if used inside QGIS in Windows XP (same data have no problems in Ubuntu 8.10). The raster are displayed in the map but data with values between (for example) -40 and 2 seem to became 5.63631e-315 ...

Change History (3)

comment:1 Changed 13 years ago by warmerdam

Cc: warmerdam added
Owner: changed from osgeo4w-dev@… to jef

I have confirmed this problem within QGIS for the spearfish slope (floating point) layer.

Oddly, when I switch to the gdal16 environment and try to access the slope layer directly from GDAL I get:

c:\warmerda\grassdb\spearfish60\PERMANENT>gdalinfo c:/warmerda/grassdb/spearfish60/PERMANENT/cellhd/aspect
gdalinfo c:/warmerda/grassdb/spearfish60/PERMANENT/cellhd/aspect
Warning 1: GRASS warning: Fail of initial read of compressed file [aspect in PERMANENT]
Warning 1: GRASS warning: Unable to open raster map <aspect@PERMANENT>
Warning 1: GRASS: Cannot open raster 'aspect'
Warning 1: GRASS: Cannot open raster band 0
gdalinfo failed - unable to open 'c:/warmerda/grassdb/spearfish60/PERMANENT/cellhd/aspect'.
Open GDAL Datasets:
  1 N DriverIsNULL      -1 634x478x0 

It would appear reading the cellhd file worked, but then something else went wrong. Any ideas on why this might be?

Turning over to Jurgen who I presume built the gdal16-grass plugin package.

comment:2 in reply to:  1 Changed 13 years ago by jef

A few notes:

  • I don't see the reported problem, when linking the plugin against the MinGW built libraries, but trying to add a raster layer triggers a crash.
  • Suspecting a compiler problem I compiled the GRASS libraries using MSVC. Using those I can add rasters into QGIS, but the reported problem appears.
  • I've tracked the problem with the MinGW libraries down and found two GRASS issues and fixed them (http://trac.osgeo.org/grass/ticket/468 and http://trac.osgeo.org/grass/ticket/469).
  • I'm going to rebuild GRASS, the GDAL plugin and QGIS with GDAL 1.5 and upload new packages soon.

comment:3 Changed 13 years ago by jef

Resolution: fixed
Status: newclosed

should be fixed in grass-6.4.0RC3-2 using the patch attached to http://trac.osgeo.org/grass/ticket/469

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