[GRASS-dev] [GRASS GIS] #3352: Behavior of v.sort.points

GRASS GIS trac at osgeo.org
Sat May 27 09:01:49 PDT 2017


#3352: Behavior of v.sort.points
--------------------------+-------------------------
  Reporter:  spawley      |      Owner:  grass-dev@…
      Type:  defect       |     Status:  closed
  Priority:  normal       |  Milestone:  7.4.0
 Component:  Addons       |    Version:  unspecified
Resolution:  fixed        |   Keywords:
       CPU:  Unspecified  |   Platform:  Linux
--------------------------+-------------------------

Comment (by mlennert):

 Replying to [ticket:3352 spawley]:
 > Hello devs,
 >
 > I appear to be having some problems with the add on v.sort.points. Two
 issues, potentially bugs:
 >
 > (1) the module fails if the 'cat' column is not the first attribute in
 the table (i.e. if points have been generated from a database table),
 returning the error:
 >
 > 'Error in sqlite3_prepare(): duplicate column name: cat'

 Try r71147. This should hopefully fix that issue.



 > (2) even if 'cat' is the first column, sorting by an integer column does
 not appear to be sorting point datasets in numeric order. Example from the
 nc_spm location:
 >
 > v.sort.points input=firestations at PERMANENT output=firestations_sorted
 column=ID
 >
 > The order of the points based on opening the attribute table, and the
 relationship between the 'ID' column and 'cat' appears to be the same as
 the original dataset, where 'ID' was not in ascending order.

 This is not a bug: cat values are conserved, i.e. the same points have the
 same cat value in the input and the output. However, points are in a
 different order in the file after v.sort.points. Category values of
 objects do not define order.

 Moritz

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Ticket URL: <https://trac.osgeo.org/grass/ticket/3352#comment:2>
GRASS GIS <https://grass.osgeo.org>



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