@turf/planepoint
planepoint
Takes a triangular plane as a Polygon
and a Point within that triangle and returns the zvalue
at that point. The Polygon should have properties a
, b
, and c
that define the values at its three corners. Alternatively, the zvalues
of each triangle point can be provided by their respective 3rd coordinate
if their values are not provided as properties.
Parameters

point
Coord the Point for which a zvalue will be calculated 
triangle
Feature<Polygon> a Polygon feature with three vertices
Examples
var point = turf.point([75.3221, 39.529]);
// "a", "b", and "c" values represent the values of the coordinates in order.
var triangle = turf.polygon([[
[75.1221, 39.57],
[75.58, 39.18],
[75.97, 39.86],
[75.1221, 39.57]
]], {
"a": 11,
"b": 122,
"c": 44
});
var zValue = turf.planepoint(point, triangle);
point.properties.zValue = zValue;
//addToMap
var addToMap = [triangle, point];
Returns number the zvalue for interpolatedPoint
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/planepoint
Or install the Turf module that includes it as a function:
$ npm install @turf/turf