Visualise velocity data on a leaflet layer
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Latest commit 5193411 Dec 18, 2017

leaflet-velocity NPM version NPM Downloads

A plugin for Leaflet (v1.0.3, and v0.7.7) to create a canvas visualisation layer for direction and intensity of arbitrary velocities (e.g. wind, ocean current).

Live Demo:

  • Uses a modified version of WindJS for core functionality.
  • Similar to wind-js-leaflet, however much more versatile (provides a generic leaflet layer, and not restricted to wind).
  • Data input format is the same as output by wind-js-server, using grib2json.


Example use:

var velocityLayer = L.velocityLayer({
	displayValues: true,
	displayOptions: {
		velocityType: 'Global Wind',
		position: 'bottomleft',
		emptyString: 'No velocity data',
		angleConvention: 'bearingCW',
		displayPosition: 'bottomleft',
		displayEmptyString: 'No velocity data',
		speedUnit: 'kt'
	data: data,             // see demo/*.json, or wind-js-server for example data service
	minVelocity: 0,          // used to align color scale
	maxVelocity: 10,         // used to align color scale
	velocityScale: 0.005,    // modifier for particle animations, arbitrarily defaults to 0.005
	colorScale: []          // define your own array of hex/rgb colors

The angle convention option refers to the convention used to express the wind direction as an angle from north direction in the control. It can be any combination of bearing (angle toward which the flow goes) or meteo (angle from which the flow comes), and CW (angle value increases clock-wise) or CCW (angle value increases counter clock-wise). If not given defaults to bearingCCW.

The speed unit option refers to the unit used to express the wind speed in the control. It can be m/s for meter per second, k/h for kilometer per hour or kt for knots. If not given defaults to m/s.


leaflet-velocity is possible because of things like:

Example data

Data shown for the Great Barrier Reef has been derived from CSIRO's eReefs products


MIT License (MIT)