[GRASS-dev] [GRASS GIS] #3043: Change default color table

[GRASS GIS]

#3043: Change default color table
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  Reporter:  wenzeslaus   |      Owner:  grass-dev@…
      Type:  enhancement  |     Status:  new
  Priority:  blocker      |  Milestone:  7.2.0
 Component:  Raster       |    Version:  svn-trunk
Resolution:               |   Keywords:  r.colors, d.rast, rainbow
       CPU:  Unspecified  |   Platform:  Unspecified
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Comment (by mlennert):

 Replying to [comment:12 wenzeslaus]:
 > Replying to [comment:11 mlennert]:
 > > One aspect your review doesn't seem to take into account is
 categorized maps. Many of the above arguments only relate to continuous,
 quantitative values, not qualitative data (and the landuse map in viridis
 is not very nice... ;-)),
 >
 > Right, I did not address them explicitly and I didn't looked at those
 specifically, but most of the things apply to categorical (qualitative) as
 well. Also I think that in case of categorical as well as diverging data
 (e.g. difference), it is easier for user to realize that a special color
 table is needed. viridis is not ideal but would work better than gray I
 think.

 You really do like viridis, it seems ;-)

 >
 > > but I guess this is impossible to detect automatically, so different
 defaults for different types of maps does not make sense.
 >
 > Well, in the current code, there are in fact separate calls for CELL and
 FCELL+DCELL (`Rast_map_is_fp()` is used). So, if we say that CELL map are
 categorical, they could be separate. I'm not sure how big assumption that
 would be. If CELL==categorical, separate tables would be easy to add
 unless I'm missing something.
 (source:grass/trunk/lib/raster/color_read.c?rev=68564#L55)

 I thought about this. I think there are sufficient quantitative variables
 that are integers (just imagine a DEM with 1m vertical precision) to make
 this assumption (CELL = categorical) a bit dangerous.

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Ticket URL: <https://trac.osgeo.org/grass/ticket/3043#comment:13>
GRASS GIS <https://grass.osgeo.org>