[GRASS-dev] [GRASS GIS] #2428: r.external to accept gdal config options

GRASS GIS trac at osgeo.org
Mon Oct 19 13:03:40 PDT 2015


#2428: r.external to accept gdal config options
--------------------------+-------------------------
  Reporter:  perrygeo     |      Owner:  grass-dev@…
      Type:  enhancement  |     Status:  new
  Priority:  normal       |  Milestone:  7.1.0
 Component:  Default      |    Version:  svn-trunk
Resolution:               |   Keywords:  r.external
       CPU:  x86-64       |   Platform:  Unspecified
--------------------------+-------------------------

Comment (by dylan):

 Replying to [comment:5 glynn]:
 > Replying to [comment:4 dylan]:
 > > Could this same block of code be used within `r.external`? I don't
 fully understand how `r.external` works, so I suppose that it is more
 complicated than this.
 >
 > r.external itself just sets up the "link" between GRASS and the data
 file. The actual I/O occurs in lib/raster (gdal.c, open.c, get_row.c,
 close.c) when a GRASS module reads the map.
 >
 > But the data which r.external controls is per-map, while this appears to
 be a global setting. What happens when a module reads multiple GDAL-linked
 maps with different settings? It might make more sense to set this in
 Rast_init_gdal() from an environment variable or $GISRC variable.

 Thank you for the clarification Glynn. I think that a suitable
 environmental or GRASS variable would be ideal. Something that isn't
 widely used but *very* important when working with massive, numerous, or
 massive and numerous files. I am unable to implement but happy to test and
 document.

--
Ticket URL: <https://trac.osgeo.org/grass/ticket/2428#comment:6>
GRASS GIS <https://grass.osgeo.org>



More information about the grass-dev mailing list