intersects (Function)

Two available sets of parameters:

• First set returns true if the incoming geo.json.geometry event intersects the given geo.json.geometryFence.
• Second set returns true if the specified coordinates intersect the given geo.json.geometryFence.

Syntax

<BOOL> geo:intersects(<DOUBLE> longitude, <DOUBLE> latitude, <STRING> geo.json.geometry.fence)
<BOOL> geo:intersects(<STRING> geo.json.geometry, <STRING> geo.json.geometry.fence)

Query Parameters

Name	Description	Possible Data Types	Optional	Dynamic
longitude	Longitude of the geo location.	Double	Yes	Yes
latitude	Latitude of the geo location.	Double	Yes	Yes
geo.json.geometry	String that contains geometry type and coordinates for a GeoJSON geometry.	STRING	Yes	Yes
geo.json.geometry.fence	String that contains geometry type and coordinates for a GeoJSON geometry fence.	String	No	Yes

Example 1

geo:intersects( {'type':'Polygon','coordinates':[[[0.5, 0.5],[0.5, 1.5],[1.5, 1.5],[1.5, 0.5],[0.5, 0.5]]]} , {'type':'Polygon','coordinates':[[[0, 0],[0, 1],[1, 1],[1, 0],[0, 0]]]} )

This geo:intersects() function call checks whether the two given polygons intersect. The first polygon's vertices are [[0.5, 0.5],[0.5, 1.5],[1.5, 1.5],[1.5, 0.5],[0.5, 0.5]], and the second polygon's vertices are [[0, 0],[0, 1],[1, 1],[1, 0],[0, 0]]. As the polygons intersect, the function returns true.

Example 2

geo:intersects(0.5, 0.5 , {'type':'Polygon','coordinates':[[[0, 0],[0, 1],[1, 1],[1, 0],[0, 0]]]})

Here, the geo:intersects() function determines whether the point (0.5, 0.5) intersects the polygon defined by [[0, 0],[0, 1],[1, 1],[1, 0],[0, 0]]. Since the point is inside the polygon, the function returns true.

Example 3

CREATE STREAM InputGeoStream (geoJsonFence1 string, geoJsonFence2 string);
CREATE SINK STREAM OutputGeoStream (intersects bool);

@info(name = 'IntersectionCheckQuery')
INSERT INTO OutputGeoStream
SELECT geo:intersects(geoJsonFence1, geoJsonFence2) AS intersects
FROM InputGeoStream;

In this example, the IntersectionCheckQuery processes events from the InputGeoStream, which contains two GeoJSON fences (geoJsonFence1, geoJsonFence2). The stream worker uses the geo:intersects(geoJsonFence1, geoJsonFence2) function to check if the fences intersect. The outcome, either true or false, is output as the intersects attribute for each event to the OutputGeoStream.