turf-planepoint

turf planepoint module

turf.planepoint(interpolatedPoint, triangle)

Takes a triangular plane as a Polygon and a Point within that triangle and returns the z-value at that point. The Polygon needs to have properties a, b, and c that define the values at its three corners.

Parameters

parameter	type	description
interpolatedPoint	Feature.<Point>	the Point for which a z-value will be calculated
triangle	Feature.<Polygon>	a Polygon feature with three vertices

Example

var point = {
  "type": "Feature",
  "properties": {},
  "geometry": {
    "type": "Point",
    "coordinates": [-75.3221, 39.529]
  }
};
var point = turf.point([-75.3221, 39.529]);
// triangle is a polygon with "a", "b",
// and "c" values representing
// the values of the coordinates in order.
var triangle = {
  "type": "Feature",
  "properties": {
    "a": 11,
    "b": 122,
    "c": 44
  },
  "geometry": {
    "type": "Polygon",
    "coordinates": [[
      [-75.1221, 39.57],
      [-75.58, 39.18],
      [-75.97, 39.86],
      [-75.1221, 39.57]
    ]]
  }
};

var features = {
  "type": "FeatureCollection",
  "features": [triangle, point]
};

var zValue = turf.planepoint(point, triangle);

//=features

//=zValue

Returns Number, the z-value for interpolatedPoint

Installation

Requires nodejs.

$ npm install turf-planepoint

Tests

$ npm test