[GRASS-dev] [GRASS GIS] #3184: v.vect.stats: errors in counts and statistics

[GRASS GIS]

#3184: v.vect.stats: errors in counts and statistics
-------------------------+--------------------------
  Reporter:  veroandreo  |      Owner:  grass-dev@…
      Type:  defect      |     Status:  new
  Priority:  normal      |  Milestone:  7.2.0
 Component:  Vector      |    Version:  svn-trunk
Resolution:              |   Keywords:  v.vect.stats
       CPU:  x86-64      |   Platform:  Linux
-------------------------+--------------------------

Comment (by mlennert):

 Replying to [comment:4 veroandreo]:
 > I applied the patch and tested.
 > - For my data (615 points, 3600 areas split in 325 categories), I got
 Segmentation fault.

 Yes, i just noticed this for the original test data (test_areas,
 test_points) as well...

 > - For the data generated with the commands you just posted, the result
 looks fine when running v.vect.stats with -p flag.
 >
 > {{{
 > GRASS 7.3.svn (nc_spm_08_grass7):~ > v.vect.stats -p points=gc
 type=centroid areas=grid_one_cat points_col=col countcol=count
 statscol=sum method=sum
 > Selecting points for each area...
 >  100%
 > area_cat|count|sum
 > 1|9|18
 > }}}
 >
 > However, if you remove that flag, to actually update the attribute table
 (which for this case it is supposed to have only one category), I get:
 >
 > {{{
 > GRASS 7.3.svn (nc_spm_08_grass7):~ > v.db.select grid_one_cat
 > cat|row|col|rown|coln|count|sum
 > 1|3|1|C|A|9|18
 > 2|3|2|C|B||
 > 3|3|3|C|C||
 > 4|2|1|B|A||
 > 5|2|2|B|B||
 > 6|2|3|B|C||
 > 7|1|1|A|A||
 > 8|1|2|A|B||
 > 9|1|3|A|C||
 > }}}
 >
 > Is there something wrong with v.db.select or with v.edit? I followed all
 your steps. But even if I do {{{v.db.select grid_one_cat}}} before
 v.vect.stats (and after the v.edit step), I get all the old categories:
 >
 > {{{
 > GRASS 7.3.svn (nc_spm_08_grass7):~ > v.db.select grid_one_cat
 > cat|row|col|rown|coln
 > 1|3|1|C|A
 > 2|3|2|C|B
 > 3|3|3|C|C
 > 4|2|1|B|A
 > 5|2|2|B|B
 > 6|2|3|B|C
 > 7|1|1|A|A
 > 8|1|2|A|B
 > 9|1|3|A|C
 > }}}
 >
 > I'm lost...

 This is normal: the table is not changed by the v.category commands, only
 the cat values. So all the old entries are still there. To make it really
 clean, one would have to run v.db.connect -d, db.droptable, v.db.addtable
 after the v.category command.

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Ticket URL: <https://trac.osgeo.org/grass/ticket/3184#comment:5>
GRASS GIS <https://grass.osgeo.org>