[GRASS-dev] [GRASS GIS] #517: v.net.iso / v.net.alloc: keep original cat values or change output to field in attribute table instead of new map

[GRASS GIS]

#517: v.net.iso / v.net.alloc: keep original cat values or change output to field
in attribute table instead of new map
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  Reporter:  effilc36     |      Owner:  grass-dev@…
      Type:  enhancement  |     Status:  new
  Priority:  minor        |  Milestone:  7.4.0
 Component:  Vector       |    Version:  svn-trunk
Resolution:               |   Keywords:  v.net.iso
       CPU:  All          |   Platform:  All
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Comment (by mmetz):

 Replying to [comment:8 mlennert]:
 > Pinging this after a class where many students thought they did
 something wrong because the approach using cat values is not very
 intuitive and is not directly visible.
 >
 > I still think that giving the option to write the results as new columns
 in the attribute file of the network would be a nice feature to have.

 v.net.iso and v.net.alloc split some of the input lines: if the start node
 and the end node of a line belong to different classes, that line is split
 proportional to the cost difference and the two (or more) new lines will
 belong to different classes.

 Therefore it is not possible to simply add a new attribute to input lines.

 What could be done is to add a new flag that 1) creates unique categories
 and adds an attribute table with class id (iso zone) and distance, 2)
 copies original arc attributes to a separate layer with some lines sharing
 the original arc category.

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Ticket URL: <https://trac.osgeo.org/grass/ticket/517#comment:9>
GRASS GIS <https://grass.osgeo.org>