Question

Calculate distance using attribute

F
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Hi

I have a polygon with name A and some points around with names A, B , C, D

I would like to calculate the distance between the centerpoint of polygon and the point with the same name of polygon (distance polygon A point A)

Thx

Francesco

3 replies

erik_jan
Rank
Userlevel 2
Badge +16

Replace the polygon with the center point (CenterPointReplacer).

Then use the NeighborFinder (group by name) to find the closest point (candidate) to the centerpoint (base).

This will add an attribute _distance, with the requested distance.

G
Badge +3

@frsisani

Or extract centerpoint (CenterPointReplacer)

FeatureMerge unconditionaly (req = 1 and sup = 1) to points.

Create lines Vertex replace with centerpoint and Vertex add with points.

Function @Length() holds the distance (can ber accesed via Aritmetic Editor in all transformer that provide acces to this editor, for instance tester or Attributecreator).

takashi
Rank
Userlevel 2
Badge +17

Alternatively, this procedure is also possible. This is a way to calculate distance literally using attributes.

  1. CenterPointExtractor: Extract coordinates (x0, y0) of center point from each polygon. 
  2. CoordinatExtractor: Extract coordinates (x1, y1) from each point.
  3. FeatureMerger: Merge (x1, y1) to polygon feature using their name (A, B, C ...) as Join On. 
  4. ExpressionEvaluator: Calculate the distance between (x0, y0) and (x1, y1) with this math expression. The AttributeCreator or the AttributeManager can also be used here.
@hypot((@Value(x1)-@Value(x0)),(@Value(y1)-@Value(y0)))

0684Q00000ArJypQAF.png

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