[GRASS-dev] [GRASS GIS] #3221: r.cross output misses one category

[GRASS GIS]

#3221: r.cross output misses one category
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 Reporter:  pvanbosgeo   |      Owner:  grass-dev@…
     Type:  defect       |     Status:  new
 Priority:  normal       |  Milestone:  7.0.6
Component:  Default      |    Version:  unspecified
 Keywords:               |        CPU:  Unspecified
 Platform:  Unspecified  |
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 I have two layers with 2 categories (1 and 2) each. When combined using
 r.cross the output is a map with three categories according to the message
 on the command line. Also, the map created has three colours.

 Yet, there should be four categories, and there is indeed a fourth
 category with value 0 (but without category label)

 {{{
 r.stats -l input=grevrobenvclust
 0
 1 category 1; category 2
 2 category 2; category 1
 3 category 2; category 2
 * no data
 }}}

 This category 0 is the area where both layers have a value 1. See also the
 attached screenshot.

 So there are the problems that:

 * only three categories are reported, while there are four in reality
 * one (the first) category has no category label with the values of the
 input maps
 * the category 0 (without category label) is assigned the same colour as
 category 3
 * When running the tool to create interactively the colour table, colours
 are only assigned to categories 1-3, so the category 0 should not have a
 colour (see attached screenshot). Clicking the 'apply' button without
 changing the categories, and the category 0 will indeed disappear from the
 map.

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Ticket URL: <https://trac.osgeo.org/grass/ticket/3221>
GRASS GIS <https://grass.osgeo.org>