[GRASS-dev] Re: [GRASS GIS] #73: r.out.gdal tiff output does not work

[GRASS GIS]

#73: r.out.gdal tiff output does not work
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  Reporter:  helena  |       Owner:  grass-dev at lists.osgeo.org
      Type:  defect  |      Status:  new                      
  Priority:  major   |   Milestone:  6.5.0                    
 Component:  Raster  |     Version:  svn-trunk                
Resolution:          |    Keywords:  r.out.gdal, tiff         
  Platform:  All     |         Cpu:  All                      
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Comment (by hamish):

 Replying to [comment:49 mmetz]:
 >    - NaN for all GDAL floating point datatypes. Is NaN
 > constructed with 0.0/0.0 ok?

 yes (AFAIK)

 >    - GDAL signed int types: first try minimum in potential range, if
 raster_min <= type_min, try maximum in potential range, if raster_max >=
 type_max, use minimum (would be (GInt32) 0x80000000 for GDT_Int32). This
 can re-use results of range check above.
 >    - GDAL unsigned int types: first try maximum in potential range, if
 raster_max >= type_max, try minimum in potential range, if raster_min <=
 type_min, use maximum. This can re-use results of range check above.

 it all seems a bit complicated, but ok.

 >  * before actual export, in case of custom nodata make sure the metadata
 nodata value and the raster nodata value are identical

 why? if custom nodata then export NULLs in the map to be the custom value
 and clobber any real data which had that value.
 (perhaps I don't understand something here..)


 >    - if (nodata != (double) (GDAL datatype) nodata) -> warning and
 nodata = (double) (GDAL datatype) nodata

 if the user asks to use a certain nodata value and it is illegal for the
 data type then exit with an error, probably giving the available range in
 the error message. don't automagically correct it for them and continue
 (ie override their expressed wishes). It is a recipe for pain.


 >    - if there are cells == nodata value and NULL cells were assigned
 that nodata value -> -f flag and user nodata value: warning, else error

 ok


 > Hamish, what exactly should this compatibility flag do? There
 > is all sorts of software with all sorts of different
 > deficiencies out there...

 umm, I forget what that was in reference to. ??minimalistic metadata
 output??



 is everyone happy with the colortable export stuff now?
 (my only issue with it is that if you pass the no-metadata create
 option to GDAL, GRASS adds its stuff anyway)


 I shifted the bug target to 6.5 as this needs testing before going into
 6.4.0 (this is a substantial last-minute change to a core module & we
 can't keep on resetting the RC cycle + we seem to have survived with it
 as-was for this long...). Strong candidate for 6.4.1.


 thanks,
 Hamish

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Ticket URL: <https://trac.osgeo.org/grass/ticket/73#comment:52>
GRASS GIS <http://grass.osgeo.org>