geo_angle()

Learn how to use the geo_angle() function to calculate the angle between two lines on Earth.

Calculates clockwise angle in radians between two lines on Earth. The first line is [point1, point2] and the second line is [point2, point3].

Syntax

geo_angle(p1_longitude,p1_latitude,p2_longitude,p2_latitude,p3_longitude,p3_latitude)

Parameters

NameTypeRequiredDescription
p1_longitudereal✔️The longitude value in degrees of the first geospatial coordinate. A valid value is in the range [-180, +180].
p1_latitudereal✔️The latitude value in degrees of the first geospatial coordinate. A valid value is in the range [-90, +90].
p2_longitudereal✔️The longitude value in degrees of the second geospatial coordinate. A valid value is in the range [-180, +180].
p2_latitudereal✔️The latitude value in degrees of the second geospatial coordinate. A valid value is in the range [-90, +90].
p3_longitudereal✔️The longitude value in degrees of the second geospatial coordinate. A valid value is in the range [-180, +180].
p3_latitudereal✔️The latitude value in degrees of the second geospatial coordinate. A valid value is in the range [-90, +90].

Returns

An angle in radians in range [0, 2pi) between two lines [p1, p2] and [p2, p3]. The angle is measured CW from the first line to the Second line.

Examples

The following example calculates the angle in radians.

print angle_in_radians = geo_angle(0, 10, 0,5, 3,-10)

Output

angle_in_radians
2.94493843406882

The following example calculates the angle in degrees.

let angle_in_radians = geo_angle(0, 10, 0,5, 3,-10);
print angle_in_degrees = degrees(angle_in_radians)

Output

angle_in_degrees
168.732543198009

The following example returns null because 1st point equals to 2nd point.

print is_null = isnull(geo_angle(0, 10, 0, 10, 3, -10))

Output

is_null
True