Bug report #17203
v.dissolve is "reclassifying" attributes after dissolve
|Affected QGIS version:||2.18.13||Regression?:||No|
|Operating System:||Easy fix?:||No|
|Pull Request or Patch supplied:||No||Resolution:||invalid|
|Crashes QGIS or corrupts data:||No||Copied to github as #:||25102|
I have a polygon with 5 features, classified 1-5, with 1 being light yellow gradating to 5 being dark blue. Some are split in half (see right half of first screenshot) so I dissolve by attribute using v.dissolve. The resulting output consistently "reclassifies" my 5 features like so:
1 (light yellow) becomes -> 5 (dark blue)
2 (green) -> 1 (light yellow)
3 (blue-green) -> stays as 3!
4 (mid blue) -> stays as 4
5 (dark blue) -> 2 (green)
You can see the attribute & corresponding color changes in the second screenshot. The dissolve worked great (the seams between polygons are gone), only the attributes were all shuffled around! I checked my polygons for any errors and there don't appear to be any so I believe it may be the dissolve function.
After v.dissolve (feature attributes are reclassified)
PS - this is my first bug report issued, so please let me know if there is anything to be fixed or done better in this report.
#2 Updated by Sarah Popov over 3 years ago
Giovanni Manghi wrote:
Can you attached the data?
You did the operation within the GRASS plugin or in the Processing toolbox?
Have you tried different dissolve tools in the Processing toolbox?
I've tried to replicate this but I can't - I guess I just was having a bad GIS day that day. Can you close this ticket?