[GRASS-dev] [GRASS GIS] #1124: v.to.rast inconsistency in importing label

[GRASS GIS]

#1124: v.to.rast inconsistency in importing label
-----------------------+------------------------------
  Reporter:  cmbarton  |      Owner:  grass-dev@…
      Type:  defect    |     Status:  new
  Priority:  major     |  Milestone:  6.4.6
 Component:  Raster    |    Version:  svn-develbranch6
Resolution:            |   Keywords:  v.to.rast
       CPU:  All       |   Platform:  All
-----------------------+------------------------------

Comment (by mmetz):

 Replying to [comment:6 cmbarton]:
 > There is no reason why only a map with integer values should have labels
 and a map with float values should not. Sometimes discrete data are coded
 with real numbers for a variety of reasons. Having labels for these values
 should not be arbitrarily prohibited.

 According to the manual of r.category, floating point values are fine. The
 problem is a bug in v.to.rast which writes out ranges for labels instead
 of unique labels. The cats file contains something like
 {{{
 1.5:2:first line
 2:2.5:second line
 2.5:3:third line
 }}}
 that is, 3 ranges for 4 values, and the last label got lost. v.to.rast
 should instead write out unique labels as
 {{{
 1.5:first line
 2:second line
 2.5:third line
 3:fourth line
 }}}
 Further on, v.to.rast should remove duplicate values before creating
 raster categories, otherwise the result could be something like
 {{{
 1.5:first line
 1.5:first line
 2:second line
 1.5:first line
 2.5:third line
 1.5:first line
 3:fourth line
 1.5:first line
 }}}

--
Ticket URL: <http://trac.osgeo.org/grass/ticket/1124#comment:7>
GRASS GIS <https://grass.osgeo.org>