Maps API for JavaScript Developer's Guide

H.data.heatmap.Colors

Class Summary

This class defines a standard way to customize the colors displayed in a heat map by associating custom colors with the normalized "heat" values.

[ For full details, see the Class Details ]

Property Summary

Table 1. Properties
Properties

static DEFAULT : {H.data.heatmap.Colors}

This static member defines the default heat map colors. It uses color interpolation and has the following color stops:

Class Description

This class defines a standard way to customize the colors displayed in a heat map by associating custom colors with the normalized "heat" values.

It associates colors with "heat" values via the stops property. This property is a map, where the keys are numbers ranging from 0 to 1, inclusive, and the values are colors associated with these numeric values. The colors are represented using CSS syntax, that is hexadecimal notation ("#RGB" or "#RRGGBB") or rgb(a) notation ("rgba(R, G, B, A)"), etc. The range [0 .. 1] stands for the normalized "heat" value.

Example

var colors = new H.data.heatmap.Colors({
  '0': 'rgba(255, 0, 0, 0.5)',   // half-transparent red
  '0.5': 'rgba(255, 255, 0, 0.5)', // half-transparent yellow
  '1': 'rgba(255, 255, 255, 0.5)'  // half-transparent white
  },
  true  // interpolate between the stops to create a smooth color gradient
);

Constructor Details

H.data.heatmap.Colors(stops, opt_interpolate)

Parameters:
 
stops:
{Object<string, string>}
 
An object defining the color stops
opt_interpolate:
{boolean=} [optional]
 
A value indicating whether interpolation is to be used to display smooth color transitions in the heat map (true) or whether the heat map is to be posterized (false), the default is false.
Throws:
 
{H.lang.InvalidArgumentError}
 
If color stops are not specified, if the object is empty, or the object uses incorrect syntax.

Property Details

static DEFAULT: {H.data.heatmap.Colors}

This static member defines the default heat map colors. It uses color interpolation and has the following color stops:

Example

{
 '0':   '#008', // dark blue
 '0.2': '#0b0', // medium green
 '0.5': '#ff0', // yellow
 '0.7': '#f00'  // red
}