Point_in_polygon

geometric-functions point_in_polygon

syntax

• point_in_polygon(point_data_item, polygon_data_item)

definition

point_in_polygon(point_data_item, polygon_data_item) results for each point of the point_data_item in a relation towards the domain-unit of the polygon_data_item in which the point is located.

The resulting values-unit is the domain unit of the polygon_data_item.

If a point is not located in any polygon, the function results in a null value (the yellow point in the image). If a point is located in multiple polygons, the function results in the ‘first’ relation found. As the function uses a tile specific spatial index, the concept of what is first is dependent on the tile division. With the same tile division, the function is deterministic, but if the tile division is changed this can influence the results of this point_in_polygon function. If you want to explicitly configure the ranking of the polygons in these cases, use the point_in_ranked_polygon function.

description

The point_in_polygon function was used in earlier versions of the GeoDMS to rasterize polygon data. Since version 6.025, it is advised to use the poly2grid function for this purpose.

applies to

• a data-item point_data_item with Point value-type
• a data item polygon_data_item with composition type type polygon and Point value type

example

attribute<district> district_rel (ADomain) := point_in_polygon(Adomain/point, district/geometry);

ADomain, nr of rows = 5

domain District, nr of rows = 7

see also

• point_in_ranked_polygon
• point_in_all_polygons