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.
npm install node-geometry-library
Features
------------
* 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.
Installation
------------
Issue following command:
``
yarn add node-geometry-library
`
npm i node-geometry-library
Usage
------------
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 }
]
*/
`
Available methods
------------PolyUtil class
*
*
*
*
*
*
---
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
`php
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
`php
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
`php
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
`php
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 meters
decode( encodedPath ) - Decodes an encoded path string into a sequence of LatLngs.
* encodedPath - string '_p~iF~ps|U_ulLnnqC_mqNvxq@'
Returns array
``php
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
`php
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
`php
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
`php
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
`php
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
`php
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
`php
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
`php
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
`php
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
`php
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 44766785529.143
``
---
Credits
-------
alexpechkarev
Support
-------
Please open an issue on GitHub
License
-------
Geometry Library Google Maps API V3 is released under the MIT License. See the bundled
LICENSE
file for details.