contains (Function)

Two available sets of parameters:

• First set returns true if the specified coordinates are contained within the geo.json.geometry.fence.
• Second set returns true if the geo.json.geometry is contained within the geo.json.geometry.fence.

Syntax

<BOOL> geo:contains(<DOUBLE> longitude, <DOUBLE> latitude, <STRING> geo.json.geometry.fence)
<BOOL> geo:contains(<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:contains(0.5, 0.5, {'type':'Polygon','coordinates':[[[0,0],[0,2],[1,2],[1,0],[0,0]]]} )

The geo:contains() function checks whether the provided point (0.5, 0.5) lies within the defined polygon. The polygon's vertices are [[0,0],[0,2],[1,2],[1,0],[0,0]]. As the point is inside the polygon, the function returns true.

Example 2

geo:contains( {'type': 'Circle', 'radius': 110575, 'coordinates':[1.5, 1.5]} , {'type':'Polygon','coordinates':[[[0,0],[0,4],[3,4],[3,0],[0,0]]]} )

In this case, geo:contains() function evaluates whether the specified circle, centered at coordinates (1.5, 1.5) with a radius of 110575, is completely enclosed by the polygon delineated by the vertices [[0,0],[0,4],[3,4],[3,0],[0,0]]. Given that the circle fits entirely within the polygon, the function returns true.

Example 3

CREATE STREAM InputGeoStream (pointLongitude double, pointLatitude double, geoJsonFence string);
CREATE SINK STREAM OutputGeoStream (isContained bool);

@info(name = 'geoContainmentCheck')
INSERT INTO OutputGeoStream
SELECT geo:contains(pointLongitude, pointLatitude, geoJsonFence) AS isContained
FROM InputGeoStream;

In this stream worker example, InputGeoStream is created to feed input data, which includes the geographical coordinates (pointLongitude, pointLatitude), and a GeoJSON fence (geoJsonFence). The OutputGeoStream is then set up to receive the output.

The query named geoContainmentCheck listens for events from the InputGeoStream and applies the function geo:contains(pointLongitude, pointLatitude, geoJsonFence) to each event. This function checks whether the specified coordinates (pointLongitude, pointLatitude) lie within the boundaries defined by the geoJsonFence. The function returns true if the coordinates are contained within the fence and false otherwise.

The output, a boolean value named isContained, is then forwarded to OutputGeoStream. In essence, this query is continually assessing the containment of the provided geographical points within the GeoJSON fence for each incoming event from InputGeoStream and updating OutputGeoStream accordingly.