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Simplify polyshape boundaries



polyout = simplify(polyin) returns a polyshape object made up of the boundaries of the polygon polyin with all vertex duplicates removed, and all boundary intersections and improper nesting resolved.

polyout = simplify(polyin,'KeepCollinearPoints',TF) specifies whether to keep or remove collinear points in polyout.


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Create and plot a polygon that contains a boundary intersection.

P = [0 0; 1 1; 1 0; 0.5 0.5; 0 1; 0 0];
polyin = polyshape(P,'Simplify',false)
polyin = 
  polyshape with properties:

      Vertices: [5x2 double]
    NumRegions: 1
      NumHoles: 0


Figure contains an axes. The axes contains an object of type polygon.

Use the simplify function to remove the intersection, which produces a well-defined polygon. Simplifying the polygon maintains the boundary shape, but splits the polygon into two distinct regions.

polyout = simplify(polyin)
polyout = 
  polyshape with properties:

      Vertices: [7x2 double]
    NumRegions: 2
      NumHoles: 0

Input Arguments

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Data Types: polyshape

Collinear vertices indicator, specified as false or true:

  • false — Remove collinear points so that the output polyshape contains the fewest vertices necessary to define the boundaries.

  • true — Keep all collinear points as vertices.

When the 'KeepCollinearPoints' parameter is not specified, its value is automatically set to the value used when creating the input polyshape.

Data Types: logical

Introduced in R2017b