@turf/point-on-line

@turf/point-on-line

pointOnLine

Takes a Point and a LineString and calculates the closest Point on the LineString.

Parameters

• line Feature<LineString> line to snap to
• pt Feature<Point> point to snap from
• units [string] can be degrees, radians, miles, or kilometers (optional, default kilometers)

Examples

var line = {
  "type": "Feature",
  "properties": {},
  "geometry": {
    "type": "LineString",
    "coordinates": [
      [-77.031669, 38.878605],
      [-77.029609, 38.881946],
      [-77.020339, 38.884084],
      [-77.025661, 38.885821],
      [-77.021884, 38.889563],
      [-77.019824, 38.892368]
    ]
  }
};
var pt = {
  "type": "Feature",
  "properties": {},
  "geometry": {
    "type": "Point",
    "coordinates": [-77.037076, 38.884017]
  }
};

var snapped = turf.pointOnLine(line, pt, 'miles');
snapped.properties['marker-color'] = '#00f'

var result = {
  "type": "FeatureCollection",
  "features": [line, pt, snapped]
};

//=result

Returns Feature<Point> closest point on the line to point. The properties object will contain three values: index: closest point was found on nth line part, dist: distance between pt and the closest point, location: distance along the line between start and the closest point.

---

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 module individually:

$ npm install @turf/point-on-line

Or install the Turf module that includes it as a function:

$ npm install @turf/turf