Sub (difference)

Geometric functions sub (difference)

syntax

  • sub(polygon_data_itemA, polygon_data_itemB)
  • polygon_data_itemA - polygon_data_itemB

definition

sub(polygon_data_itemA, polygon_data_itemB) or polygon_data_itemA - polygon_data_itemB results in a new Polygon Data item with the difference of the two arguments: polygon_data_itemA and polygon_data_itemB.

The resulting polygon is the original polygon (polygon_data_itemA) minus its intersection with polygon_data_itemB.

description

The sub-function can, for example, be used to create a mask polygon.

applies to

data items polygon_data_itemA and polygon_data_itemB with an ipoint or spoint Value type. A dpoint or fpoint is also allowed since version 15.6.0.

conditions

  1. The composition type of the argument items needs to be polygon.
  2. The domain of the arguments must match or be Void.

since version

  • 7.112
  • 15.6.0 (in case of floating point coordinates)

example 

parameter<ipoint> geometry (poly) := square/geometry[0] - union_polygon/geometry;

see also