[GRASS-dev] Re: [GRASS GIS] #788: r.out.gdal and nodata

[Markus Metz]

trac server gives problems, doesn't send new comment to list, see

https://trac.osgeo.org/grass/ticket/788#comment:7


GRASS GIS wrote:
> #788: r.out.gdal and nodata
> ----------------------+-----------------------------------------------------
>   Reporter:  frankie  |       Owner:  grass-dev at lists.osgeo.org
>       Type:  defect   |      Status:  new                      
>   Priority:  normal   |   Milestone:  6.4.0                    
>  Component:  Raster   |     Version:  6.4.0 RCs                
> Resolution:           |    Keywords:  r.out.gdal, nodata       
>   Platform:  Linux    |         Cpu:  Unspecified              
> ----------------------+-----------------------------------------------------
> Comment (by hamish):
>
>  Ok sounds good. Lets go ahead and backport what's in the gr7 version to
>  gr6.5. No point in widely testing dead-end code in 6.5...
>
>  Replying to [comment:5 mmetz]:
>  > The checks during the actual export could be moved to a
>  > separate pass over all raster bands to be exported, I think
>  > this is the safest solution, then r.out.gdal does not have to
>  > bother with cleaning up and can leave all format-specific error
>  > handling to GDAL.
>
>  sounds ok to me/I could live with that. anyone else have a POV?
>
>
>  > What is missing is a region check. At the very least, r.out.gdal
>  > should make sure that at least some parts of the raster maps to
>  > be exported fall within the current region, if not, abort with
>  > error: raster map outside current region, nothing to export.
>
>  hmmm. I would not do that, it is straying away from checking for errors
>  into checking for intention. I would say that's a good idea but change it
>  to a G_warning() or G_message() instead of G_fatal_error() and just write
>  a map full of NULLs regardless. No other GRASS raster module refuses to go
>  on if you have the region (ie '''WIND'''ow) set beyond its bounds.
>
>  e.g. I have a script which tiles a raster into a series of small geotiffs.
>  say I had a region with a full raster map in the top left and another in
>  the bottom right with overlapping the corners in the middle and empty
>  space in the opposite corners. I'd want those all-NULL tiles instead of a
>  404 error.
>
>  {{{
>  |-----------------|
>  |                 |
>  |  +-----+        |
>  |  |     |        |
>  |  |   +-+-----+  |
>  |  +---|-+     |  |
>  |      |       |  |
>  |      +-------+  |
>  |-----------------|
>  }}}
>
>
>  Hamish
>
>