turf/packages/turf-interpolate

@turf/interpolate

interpolate

Takes a set of points and estimates their 'property' values on a grid using the Inverse Distance Weighting (IDW) method.

Parameters

• points FeatureCollection<Point> with known value

• cellSize number the distance across each grid point

• options Object Optional parameters (optional, default {})

  • options.gridType string defines the output format based on a Grid Type (options: 'square' | 'point' | 'hex' | 'triangle') (optional, default 'square')
  • options.property string the property name in points from which z-values will be pulled, zValue fallbacks to 3rd coordinate if no property exists. (optional, default 'elevation')
  • options.units Units used in calculating cellSize. Supports all valid Turf Units. (optional, default 'kilometers')
  • options.weight number exponent regulating the distance-decay weighting (optional, default 1)
  • options.bbox BBox Bounding Box Array [west, south, east, north] associated with the FeatureCollection. (optional, default bbox(points))

Examples

var points = turf.randomPoint(30, {bbox: [50, 30, 70, 50]});

// add a random property to each point
turf.featureEach(points, function(point) {
    point.properties.solRad = Math.random() * 50;
});
var options = {gridType: 'points', property: 'solRad', units: 'miles'};
var grid = turf.interpolate(points, 100, options);

//addToMap
var addToMap = [grid];

Returns FeatureCollection<(Point | Polygon)> grid of points or polygons with interpolated 'property'

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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/interpolate

Or install the all-encompassing @turf/turf module that includes all modules as functions:

$ npm install @turf/turf