What is @turf/boolean-point-on-line?
@turf/boolean-point-on-line is a module from the Turf.js library that allows you to determine if a given point lies on a line. This can be useful for various geospatial analyses, such as validating routes, checking if a location is on a path, or any other scenario where you need to verify point-line relationships.
What are @turf/boolean-point-on-line's main functionalities?
Check if a point is on a line
This feature allows you to check if a specific point lies on a given line. In the code sample, the point [2, 2] is checked against a line that passes through [1, 1], [3, 3], and [4, 4]. The result is true because the point lies on the line.
const turf = require('@turf/turf');
const point = turf.point([2, 2]);
const line = turf.lineString([[1, 1], [3, 3], [4, 4]]);
const isPointOnLine = turf.booleanPointOnLine(point, line);
console.log(isPointOnLine); // true
Check if a point is on a line with a tolerance
This feature allows you to check if a point is on a line within a specified tolerance. In the code sample, the point [2, 2.1] is checked against the same line with a tolerance of 0.2. The result is true because the point is within the tolerance range of the line.
const turf = require('@turf/turf');
const point = turf.point([2, 2.1]);
const line = turf.lineString([[1, 1], [3, 3], [4, 4]]);
const isPointOnLine = turf.booleanPointOnLine(point, line, { tolerance: 0.2 });
console.log(isPointOnLine); // true
Other packages similar to @turf/boolean-point-on-line
point-in-polygon
The 'point-in-polygon' package allows you to check if a point is inside a polygon. While it doesn't check for points on lines, it is useful for similar geospatial analyses where you need to determine point-in-shape relationships.
geolib
The 'geolib' package provides a variety of geospatial functions, including checking if a point is on a line. It offers more general-purpose geospatial utilities compared to @turf/boolean-point-on-line, which is more specialized.
leaflet
Leaflet is a popular library for interactive maps. While it is primarily used for rendering maps, it also provides some geospatial analysis functions, including checking if a point is on a line. It is more comprehensive in terms of mapping capabilities compared to @turf/boolean-point-on-line.
@turf/boolean-point-on-line
booleanPointOnLine
Returns true if a point is on a line. Accepts a optional parameter to ignore the
start and end vertices of the linestring.
Parameters
-
pt
Coord GeoJSON Point
-
line
Feature<LineString> GeoJSON LineString
-
options
Object Optional parameters (optional, default {}
)
options.ignoreEndVertices
boolean whether to ignore the start and end vertices. (optional, default false
)options.epsilon
number? Fractional number to compare with the cross product result. Useful for dealing with floating points such as lng/lat points
Examples
var pt = turf.point([0, 0]);
var line = turf.lineString([[-1, -1],[1, 1],[1.5, 2.2]]);
var isPointOnLine = turf.booleanPointOnLine(pt, line);
Returns boolean true/false
This module is part of the Turfjs project, an open source module collection dedicated to geographic algorithms. It is maintained in the Turfjs/turf repository, where you can create PRs and issues.
Installation
Install this single module individually:
$ npm install @turf/boolean-point-on-line
Or install the all-encompassing @turf/turf module that includes all modules as functions:
$ npm install @turf/turf