isolines

Description

Takes a grid FeatureCollection of Point features with z-values and an array of value breaks and generates isolines.

Parameters

Name	Type	Description
pointGrid	FeatureCollection<Point>	input points
breaks	Array<number>	values of zProperty where to draw isolines
options?	Object	Optional parameters (default {})
options.zProperty?	string	the property name in points from which z-values will be pulled (default 'elevation')
options.commonProperties?	Object	GeoJSON properties passed to ALL isolines (default {})
options.breaksProperties?	Array<Object>	GeoJSON properties passed, in order, to the correspondent isoline; the breaks array will define the order in which the isolines are created (default [])

Returns

FeatureCollection<MultiLineString> a FeatureCollection of MultiLineString features representing isolines

Examples

// create a grid of points with random z-values in their properties
var extent = [0, 30, 20, 50];
var cellWidth = 100;
var pointGrid = turf.pointGrid(extent, cellWidth, { units: "miles" });

for (var i = 0; i < pointGrid.features.length; i++) {
  pointGrid.features[i].properties.temperature = Math.random() * 10;
}
var breaks = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10];

var lines = turf.isolines(pointGrid, breaks, { zProperty: "temperature" });

Installation

$ npm install @turf/isolines

import { isolines } from "@turf/isolines";
const result = isolines(...);

$ npm install @turf/turf

import * as turf from "@turf/turf";
const result = turf.isolines(...);