OpenLayers

Class: Heatmap

ol/layer/Heatmap~Heatmap 


import Heatmap from 'ol/layer/Heatmap';

Layer for rendering vector data as a heatmap. Note that any property set in the options is set as a module:ol/Object~BaseObject property on the layer object; for example, setting title: 'My Title' in the options means that title is observable, and has get/set accessors.

new Heatmap(opt_options)

layer/Heatmap.js, line 74
Name Type Description
options

Options.

Name Type Default Description
opacity number 1

Opacity (0, 1).
visible boolean true

Visibility.
extent module:ol/extent~Extent

The bounding extent for layer rendering. The layer will not be rendered outside of this extent.
zIndex number

The z-index for layer rendering. At rendering time, the layers will be ordered, first by Z-index and then by position. When undefined, a zIndex of 0 is assumed for layers that are added to the map's layers collection, or Infinity when the layer's setMap() method was used.
minResolution number

The minimum resolution (inclusive) at which this layer will be visible.
maxResolution number

The maximum resolution (exclusive) below which this layer will be visible.
gradient Array.<string> ['#00f', '#0ff', '#0f0', '#ff0', '#f00']

The color gradient of the heatmap, specified as an array of CSS color strings.
radius number 8

Radius size in pixels.
blur number 15

Blur size in pixels.
shadow number 250

Shadow size in pixels.
weight string | function 'weight'

The feature attribute to use for the weight or a function that returns a weight from a feature. Weight values should range from 0 to 1 (and values outside will be clamped to that range).
renderMode module:ol/layer/VectorRenderType | string 'vector'

Render mode for vector layers:

  • 'image': Vector layers are rendered as images. Great performance, but point symbols and texts are always rotated with the view and pixels are scaled during zoom animations.
  • 'vector': Vector layers are rendered as vectors. Most accurate rendering even during animations, but slower performance.
source module:ol/source/Vector~VectorSource

Source.
Fires:

Extends

Observable Properties

Name Type Settable ol/Object.ObjectEvent type Description
blur number yes change:blur

Blur size in pixels.
extent module:ol/extent~Extent | undefined yes change:extent

The layer extent.
gradient Array.<string> yes change:gradient

Colors.
maxResolution number yes change:maxresolution

The maximum resolution of the layer.
minResolution number yes change:minresolution

The minimum resolution of the layer.
opacity number yes change:opacity

The opacity of the layer.
radius number yes change:radius

Radius size in pixel.
source module:ol/source/Source~Source yes change:source

The layer source (or null if not yet set).
visible boolean yes change:visible

The visibility of the layer.
zIndex number yes change:zindex

The Z-index of the layer.

Methods

getBlur(){number}

layer/Heatmap.js, line 196

Return the blur size in pixels.

Returns:
Blur size in pixels.

getGradient(){Array.<string>}

layer/Heatmap.js, line 206

Return the gradient colors as array of strings.

Returns:
Colors.

getRadius(){number}

layer/Heatmap.js, line 216

Return the size of the radius in pixels.

Returns:
Radius size in pixel.

getSource(){module:ol/source/Vector~VectorSource} inherited

layer/Vector.js, line 256

Return the associated vectorsource of the layer.

Returns:
Source.

getStyle(){module:ol/style/Style~StyleLike} inherited

layer/Vector.js, line 187

Get the style for features. This returns whatever was passed to the style option at construction or to the setStyle method.

Returns:
Layer style.

getStyleFunction(){module:ol/style/Style~StyleFunction|undefined} inherited

layer/Vector.js, line 196

Get the style function.

Returns:
Layer style function.

setBlur(blur)

layer/Heatmap.js, line 262

Set the blur size in pixels.

Name Type Description
blur number

Blur size in pixels.

setGradient(colors)

layer/Heatmap.js, line 272

Set the gradient colors as array of strings.

Name Type Description
colors Array.<string>

Gradient.

setRadius(radius)

layer/Heatmap.js, line 282

Set the size of the radius in pixels.

Name Type Description
radius number

Radius size in pixel.

setStyle(style) inherited

layer/Vector.js, line 234

Set the style for features. This can be a single style object, an array of styles, or a function that takes a feature and resolution and returns an array of styles. If it is undefined the default style is used. If it is null the layer has no style (a null style), so only features that have their own styles will be rendered in the layer. See module:ol/style for information on the default style.

Name Type Description
style module:ol/style/Style~Style | Array.<module:ol/style/Style~Style> | module:ol/style/Style~StyleFunction | null | undefined

Layer style.