# Bubble Chart

A bubble chart is used to display three dimensions of data at the same time. The location of the bubble is determined by the first two dimensions and the corresponding horizontal and vertical axes. The third dimension is represented by the size of the individual bubbles.

const config = {
  type: 'bubble',
  data: data,
  options: {}
};

# Dataset Properties

Namespaces:

  • data.datasets[index] - options for this dataset only
  • options.datasets.bubble - options for all bubble datasets
  • options.elements.point - options for all point elements
  • options - options for the whole chart

The bubble chart allows a number of properties to be specified for each dataset. These are used to set display properties for a specific dataset. For example, the colour of the bubbles is generally set this way.

Name Type Scriptable Indexable Default
backgroundColor Color Yes Yes 'rgba(0, 0, 0, 0.1)'
borderColor Color Yes Yes 'rgba(0, 0, 0, 0.1)'
borderWidth number Yes Yes 3
clip number|object - - undefined
data object[] - - required
drawActiveElementsOnTop boolean Yes Yes true
hoverBackgroundColor Color Yes Yes undefined
hoverBorderColor Color Yes Yes undefined
hoverBorderWidth number Yes Yes 1
hoverRadius number Yes Yes 4
hitRadius number Yes Yes 1
label string - - undefined
order number - - 0
pointStyle pointStyle Yes Yes 'circle'
rotation number Yes Yes 0
radius number Yes Yes 3

All these values, if undefined, fallback to the scopes described in option resolution

# General

Name Description
clip How to clip relative to chartArea. Positive value allows overflow, negative value clips that many pixels inside chartArea. 0 = clip at chartArea. Clipping can also be configured per side: clip: {left: 5, top: false, right: -2, bottom: 0}
drawActiveElementsOnTop Draw the active bubbles of a dataset over the other bubbles of the dataset
label The label for the dataset which appears in the legend and tooltips.
order The drawing order of dataset. Also affects order for tooltip and legend. more

# Styling

The style of each bubble can be controlled with the following properties:

Name Description
backgroundColor bubble background color.
borderColor bubble border color.
borderWidth bubble border width (in pixels).
pointStyle bubble shape style.
rotation bubble rotation (in degrees).
radius bubble radius (in pixels).

All these values, if undefined, fallback to the associated elements.point.* options.

# Interactions

The interaction with each bubble can be controlled with the following properties:

Name Description
hitRadius bubble additional radius for hit detection (in pixels).
hoverBackgroundColor bubble background color when hovered.
hoverBorderColor bubble border color when hovered.
hoverBorderWidth bubble border width when hovered (in pixels).
hoverRadius bubble additional radius when hovered (in pixels).

All these values, if undefined, fallback to the associated elements.point.* options.

# Default Options

We can also change the default values for the Bubble chart type. Doing so will give all bubble charts created after this point the new defaults. The default configuration for the bubble chart can be accessed at Chart.overrides.bubble.

# Data Structure

Bubble chart datasets need to contain a data array of points, each point represented by an object containing the following properties:

{
    // X Value
    x: number,
    // Y Value
    y: number,
    // Bubble radius in pixels (not scaled).
    r: number
}

Important: the radius property, r is not scaled by the chart, it is the raw radius in pixels of the bubble that is drawn on the canvas.

# Internal data format

{x, y, _custom} where _custom is the radius.

Last Updated: 5/25/2022, 2:06:57 PM