Node JS/ Javascript Geometry Library provides utility functions for the computation of geometric data on the surface of the Earth. Code ported from Google Maps Android API.
- Spherical contains spherical geometry utilities allowing you to compute angles, distances and areas from latitudes and longitudes.
- Poly utility functions for computations involving polygons and polylines.
- Encoding utilities for polyline encoding and decoding.
Issue following command:
yarn add node-geometry-library
npm i node-geometry-library
Here is an example of using GeometryLibrary:
import {SphericalUtil, PolyUtil} from "node-geometry-library";
let response = SphericalUtil.computeHeading(
{lat: 25.775, lng: -80.19}, // from object {lat, lng}
{lat: 21.774, lng: -80.19} // to object {lat, lng}
);
console.log(response) // -180
let response = SphericalUtil.computeDistanceBetween(
{lat: 25.775, lng: -80.19}, //from object {lat, lng}
{lat: 21.774, lng: -80.19} // to object {lat, lng}
);
console.log(response) // 444891.52998049
let response = PolyUtil.isLocationOnEdge(
{lat: 25.774, lng: -80.19}, // point object {lat, lng}
[
// poligon arrays of object {lat, lng}
{lat: 25.774, lng: -80.19},
{lat: 18.466, lng: -66.118},
{lat: 32.321, lng: -64.757}
]
);
console.log(response) // true
let response = PolyUtil.isLocationOnPath(
{lat: 25.771, lng: -80.19}, // point object {lat, lng}
[
// poligon arrays of object {lat, lng}
{lat: 25.774, lng: -80.19},
{lat: 18.466, lng: -66.118},
{lat: 32.321, lng: -64.757}
]
);
console.log(response) // true
let response = PolyUtil.containsLocation(
{lat: 23.886, lng: -65.269}, // point object {lat, lng}
[
// poligon arrays of object {lat, lng}
{lat: 25.774, lng: -80.19},
{lat: 18.466, lng: -66.118},
{lat: 32.321, lng: -64.757}
]
);
console.log(response) // false
let response = PolyUtil.distanceToLine(
{lat: 61.387002, lng: 23.890636}, // point object {lat, lng}
{lat: 61.487002, lng: 23.790636}, // line startpoint object {lat, lng}
{lat: 60.48047, lng: 22.052754} // line endpoint object {lat, lng}
);
console.log(response) // 12325.124046196 in meters
let response = PolyUtil.encode([
{lat: 38.5, lng: -120.2},
{lat: 40.7, lng: -120.95},
{lat: 43.252, lng: -126.453}
]);
console.log(response) // '_p~iF~ps|U_ulLnnqC_mqNvxq`@'
let response = PolyUtil.decode('_p~iF~ps|U_ulLnnqC_mqNvxq`@');
console.log(response) /**
[ { lat: 38.5, lng: -120.2 },
{ lat: 40.7, lng: -120.95 },
{ lat: 43.252, lng: -126.453 }
]
*/
containsLocation(point, polygon, geodesic = false)isLocationOnEdge(point, polygon, tolerance = PolyUtil.DEFAULT_TOLERANCE, geodesic = true)isLocationOnPath(point, polyline, tolerance = PolyUtil.DEFAULT_TOLERANCE, geodesic = true)distanceToLine(p, start, end)decode(encodedPath)encode(path)
computeHeading(from, to)computeOffset(from, distance, heading)computeOffsetOrigin(to, distance, heading)interpolate(from, to, fraction)computeDistanceBetween( from, to)computeLength(path)computeArea(path)computeSignedArea(path)
containsLocation( point, polygon, geodesic = false ) - To find whether a given point falls within a polygon
point- {'lat': 38.5, 'lng': -120.2}polygon- [ {'lat': 38.5, 'lng': -120.2}, {'lat': 40.7, 'lng': -120.95 }, {'lat': 43.252, 'lng': -126.453} ]geodesic- boolean
Returns boolean
const response = PolyUtil.containsLocation(
{'lat': 23.886, 'lng': -65.269}, // point object of {lat, lng}
[ // poligon arrays of object {lat, lng}
{'lat': 25.774, 'lng': -80.190},
{'lat': 18.466, 'lng': -66.118},
{'lat': 32.321, 'lng': -64.757}
]);
console.log(response) // false
isLocationOnEdge( point, polygon, tolerance = PolyUtil.DEFAULT_TOLERANCE, geodesic = true ) - To determine whether a point falls on or near a polyline, or on or near the edge of a polygon, within a specified tolerance in meters.
point- {'lat': 25.774, 'lng': -80.190}polygon- [{'lat': 38.5, 'lng': -120.2}, {'lat': 40.7, 'lng': -120.95}, {'lat': 43.252, 'lng': -126.453}]tolerance- tolerance value in degreesgeodesic- boolean
Returns boolean
const response = PolyUtil.isLocationOnEdge(
{'lat': 25.774, 'lng': -80.190}, // point object {lat, lng}
[ // poligon arrays of object {lat, lng}
{'lat': 25.774, 'lng': -80.190},
{'lat': 18.466, 'lng': -66.118},
{'lat': 32.321, 'lng': -64.757}
]) ;
console.log(response) // true
isLocationOnPath( point, polygon, tolerance = PolyUtil.DEFAULT_TOLERANCE, geodesic = true ) - To determine whether a point falls on or near a polyline, within a specified tolerance in meters
point- {'lat': 25.774, 'lng': -80.190}polygon- [{'lat': 38.5, 'lng': -120.2}, {'lat': 40.7, 'lng': -120.95}, {'lat': 43.252, 'lng': -126.453}]tolerance- tolerance value in degreesgeodesic- boolean
Returns boolean
response = PolyUtil.isLocationOnPath(
{'lat': 25.774, 'lng': -80.190}, // point object if {lat, lng}
[ // poligon arrays of object {lat, lng}
{'lat': 25.774, 'lng': -80.190},
{'lat': 18.466, 'lng': -66.118},
{'lat': 32.321, 'lng': -64.757}
]) ;
console.log(response) // true
distanceToLine( p, start, end ) - To calculate distance from a point to line start->end on sphere.
p- {'lat': 61.387002, 'lng': 23.890636}start- {'lat': 61.487002, 'lng': 23.790636}end- {'lat': 60.48047, 'lng': 22.052754}
Returns distance from a point to line
const response = PolyUtil.distanceToLine(
{'lat': 61.387002, 'lng': 23.890636}, // point object {lat, lng}
{'lat': 61.487002, 'lng': 23.790636}, // line start point object {lat, lng}
{'lat': 60.48047, 'lng': 22.052754}// line endpoint object {lat, lng}
);
console.log(response) // 12325.124046196 in metersdecode( encodedPath ) - Decodes an encoded path string into a sequence of LatLngs.
encodedPath- string '_piFps|U_ulLnnqC_mqNvxq`@'
Returns array
const response = PolyUtil.decode('_p~iF~ps|U_ulLnnqC_mqNvxq`@');
console.log(response);
/*
[ { lat: 38.5, lng: -120.2 },
{ lat: 40.7, lng: -120.95 },
{ lat: 43.252, lng: -126.453 }
]
*/
encode( path ) - Encodes a sequence of LatLngs into an encoded path string.
path- [ {'lat': 38.5, 'lng': -120.2}, {'lat': 40.7, 'lng': -120.95}, {'lat': 43.252, 'lng': -126.453} ]
Returns string
response = PolyUtil.encode(
[
{'lat': 38.5, 'lng': -120.2},
{'lat': 40.7, 'lng': -120.95},
{'lat': 43.252, 'lng': -126.453}
]);
console.log(response); // '_p~iF~ps|U_ulLnnqC_mqNvxq`@'
computeHeading( from, to ) - Returns the heading from one LatLng to another LatLng.
from- {'lat': 38.5, 'lng': -120.2}to- {'lat': 40.7, 'lng': -120.95}
Returns int
response = SphericalUtil.computeHeading(
{'lat': 25.775, 'lng': -80.190},
{'lat': 21.774, 'lng': -80.190}));
console.log(response); // -180
computeOffset( from, distance, heading ) - Returns the LatLng resulting from moving a distance from an origin in the specified heading.
from- {'lat': 38.5, 'lng': -120.2}distance- number, the distance to travelheading- number, the heading in degrees clockwise from north
Returns array
response = SphericalUtil.computeOffset({'lat': 25.775, 'lng': -80.190}, 152, 120);
console.log(response);
/*
{
'lat': 25.774316510639,
'lng': -80.188685385944
}
*/
computeOffsetOrigin( from, distance, heading ) - Returns the location of origin when provided with a LatLng destination, meters travelled and original heading. Headings are expressed in degrees clockwise from North.
from- {'lat': 38.5, 'lng': -120.2}distance- number, the distance to travelheading- number, the heading in degrees clockwise from north
Returns array
response = SphericalUtil.computeOffsetOrigin({'lat': 25.775, 'lng': -80.190}, 152, 120);
console.log(response);
/*
{
'lat': 14.33435503928,
'lng': -263248.24242931
}
*/
interpolate( from, to, fraction ) - Returns the LatLng which lies the given fraction of the way between the origin LatLng and the destination LatLng.
from- {'lat': 38.5, 'lng': -120.2}to- {'lat': 38.5, 'lng': -120.2}fraction- number, a fraction of the distance to travel
Returns array
response = SphericalUtil.interpolate({'lat': 25.775, 'lng': -80.190}, {'lat':26.215, 'lng': -81.218}, 2);
console.log(response);
/*
{
'lat': 26.647635362403,
'lng': -82.253737943391
}
*/
computeDistanceBetween( from, to ) - Returns the distance, in meters, between two LatLngs. You can optionally specify a custom radius. The radius defaults to the radius of the Earth.
from- {'lat': 38.5, 'lng': -120.2}to- {'lat': 38.5, 'lng': -120.2}
Returns float
response = SphericalUtil.computeDistanceBetween({'lat': 25.775, 'lng': -80.190}, {'lat': 26.215, 'lng': -81.218});
console.log(response); //float 113797.92421349
computeLength( path ) - Returns the length of the given path, in meters, on Earth.
path- [ {'lat': 38.5, 'lng': -120.2}, {'lat': 40.7, 'lng': -120.95}, {'lat': 43.252, 'lng': -126.453} ]
Returns float
const response = SphericalUtil.computeLength([
{'lat': 38.5, 'lng': -120.2},
{'lat': 40.7, 'lng': -120.95},
{'lat': 43.252, 'lng': -126.453}
]);
console.log(response); //float 788906.98459431
computeArea( path ) - Returns the area of a closed path.
path- [ {'lat': 38.5, 'lng': -120.2}, {'lat': 40.7, 'lng': -120.95}, {'lat': 43.252, 'lng': -126.453} ]
Returns float
response = SphericalUtil.computeArea([
{'lat': 38.5, 'lng': -120.2},
{'lat': 40.7, 'lng': -120.95},
{'lat': 43.252, 'lng': -126.453}
]);
console.log(response); //float 44766785529.143
computeSignedArea( path ) - Returns the signed area of a closed path.
path- [ {'lat': 38.5, 'lng': -120.2}, {'lat': 40.7, 'lng': -120.95}, {'lat': 43.252, 'lng': -126.453} ]
Returns float
response = SphericalUtil.computeSignedArea([
{'lat': 38.5, 'lng': -120.2},
{'lat': 40.7, 'lng': -120.95},
{'lat': 43.252, 'lng': -126.453}
]);
console.log(response); //float 44766785529.143Please open an issue on GitHub
Geometry Library Google Maps API V3 is released under the MIT License. See the bundled LICENSE file for details.