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Question

How to dissolve some polygons by minimizing/maximizing an attribute

  • November 12, 2018
  • 3 replies
  • 20 views

Hi,

I've a polygon feature with an attribute "LEVEL" containing values from 1 to 10.

The polygons can be overlapped.

I want to dissolve the polygon grouped by "LEVEL" and only keep the polygon with the lowest "LEVEL" value. It's easy to dissolve the polygon grouped by "LEVEL" but how to only keep the polygons with the lowest value ?

Here is an illustration of what I'm trying to do, the number correspond to the attribute "LEVEL":

 

3 replies

chrisatsafe
Contributor
Forum|alt.badge.img+2
  • Contributor
  • November 12, 2018

Hi @baschec,

Have you tried using a PolygonCutter and a Dissolver? Once the polygons are cut, you can dissolve based on the LEVEL attribute.

Input:

Output:

 

Cut_and_Dissolve.fmwt


ebygomm
Influencer
Forum|alt.badge.img+39
  • Influencer
  • November 12, 2018

Use area on area overlayer to create all the individual segments with a list containing the LEVEL, sort the list by LEVEL in ascending order then use the first element of the list to dissolve by

dissolve_lowest_value_polygons.fmwt


pabloolivaresm
Supporter
Forum|alt.badge.img+4

@ebygomm​  hi, thanks for yours answers! I have similar case but different. I have buildings polygones with height attribut, but when the height was calculated, some of then were cutted in two. I can dissolve easily because they share ID, but i can not chose to keep just the height max of both, if you have any idea i'll be grateful, thanks


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