# Radar Chart

A radar chart is a way of showing multiple data points and the variation between them.

They are often useful for comparing the points of two or more different data sets.

```js chart-editor
// <block:setup:1>
const data = {
  labels: [
    'Eating',
    'Drinking',
    'Sleeping',
    'Designing',
    'Coding',
    'Cycling',
    'Running'
  ],
  datasets: [{
    label: 'My First Dataset',
    data: [65, 59, 90, 81, 56, 55, 40],
    fill: true,
    backgroundColor: 'rgba(255, 99, 132, 0.2)',
    borderColor: 'rgb(255, 99, 132)',
    pointBackgroundColor: 'rgb(255, 99, 132)',
    pointBorderColor: '#fff',
    pointHoverBackgroundColor: '#fff',
    pointHoverBorderColor: 'rgb(255, 99, 132)'
  }, {
    label: 'My Second Dataset',
    data: [28, 48, 40, 19, 96, 27, 100],
    fill: true,
    backgroundColor: 'rgba(54, 162, 235, 0.2)',
    borderColor: 'rgb(54, 162, 235)',
    pointBackgroundColor: 'rgb(54, 162, 235)',
    pointBorderColor: '#fff',
    pointHoverBackgroundColor: '#fff',
    pointHoverBorderColor: 'rgb(54, 162, 235)'
  }]
};
// </block:setup>

// <block:config:0>
const config = {
  type: 'radar',
  data: data,
  options: {
    elements: {
      line: {
        borderWidth: 3
      }
    }
  },
};
// </block:config>

module.exports = {
  actions: [],
  config: config,
};
```

## Dataset Properties

Namespaces:

* `data.datasets[index]` - options for this dataset only
* `options.datasets.line` - options for all line datasets
* `options.elements.line` - options for all [line elements](../configuration/elements.md#line-configuration)
* `options.elements.point` - options for all [point elements](../configuration/elements.md#point-configuration)
* `options` - options for the whole chart

The radar 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 a line is generally set this way.

| Name | Type | [Scriptable](../general/options.md#scriptable-options) | [Indexable](../general/options.md#indexable-options) | Default
| ---- | ---- | :----: | :----: | ----
| [`backgroundColor`](#line-styling) | [`Color`](../general/colors.md) | Yes | - | `'rgba(0, 0, 0, 0.1)'`
| [`borderCapStyle`](#line-styling) | `string` | Yes | - | `'butt'`
| [`borderColor`](#line-styling) | [`Color`](../general/colors.md) | Yes | - | `'rgba(0, 0, 0, 0.1)'`
| [`borderDash`](#line-styling) | `number[]` | Yes | - | `[]`
| [`borderDashOffset`](#line-styling) | `number` | Yes | - | `0.0`
| [`borderJoinStyle`](#line-styling) | `'round'`\|`'bevel'`\|`'miter'` | Yes | - | `'miter'`
| [`borderWidth`](#line-styling) | `number` | Yes | - | `3`
| [`hoverBackgroundColor`](#line-styling) | [`Color`](../general/colors.md) | Yes | - | `undefined`
| [`hoverBorderCapStyle`](#line-styling) | `string` | Yes | - | `undefined`
| [`hoverBorderColor`](#line-styling) | [`Color`](../general/colors.md) | Yes | - | `undefined`
| [`hoverBorderDash`](#line-styling) | `number[]` | Yes | - | `undefined`
| [`hoverBorderDashOffset`](#line-styling) | `number` | Yes | - | `undefined`
| [`hoverBorderJoinStyle`](#line-styling) | `'round'`\|`'bevel'`\|`'miter'` | Yes | - | `undefined`
| [`hoverBorderWidth`](#line-styling) | `number` | Yes | - | `undefined`
| [`clip`](#general) | `number`\|`object` | - | - | `undefined`
| [`data`](#data-structure) | `number[]` | - | - | **required**
| [`fill`](#line-styling) | `boolean`\|`string` | Yes | - | `false`
| [`label`](#general) | `string` | - | - | `''`
| [`order`](#general) | `number` | - | - | `0`
| [`tension`](#line-styling) | `number` | - | - | `0`
| [`pointBackgroundColor`](#point-styling) | `Color` | Yes | Yes | `'rgba(0, 0, 0, 0.1)'`
| [`pointBorderColor`](#point-styling) | `Color` | Yes | Yes | `'rgba(0, 0, 0, 0.1)'`
| [`pointBorderWidth`](#point-styling) | `number` | Yes | Yes | `1`
| [`pointHitRadius`](#point-styling) | `number` | Yes | Yes | `1`
| [`pointHoverBackgroundColor`](#interactions) | `Color` | Yes | Yes | `undefined`
| [`pointHoverBorderColor`](#interactions) | `Color` | Yes | Yes | `undefined`
| [`pointHoverBorderWidth`](#interactions) | `number` | Yes | Yes | `1`
| [`pointHoverRadius`](#interactions) | `number` | Yes | Yes | `4`
| [`pointRadius`](#point-styling) | `number` | Yes | Yes | `3`
| [`pointRotation`](#point-styling) | `number` | Yes | Yes | `0`
| [`pointStyle`](#point-styling) | [`pointStyle`](../configuration/elements.md#types) | Yes | Yes | `'circle'`
| [`spanGaps`](#line-styling) | `boolean` | - | - | `undefined`

All these values, if `undefined`, fallback to the scopes described in [option resolution](../general/options)

### 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}`
| `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](mixed.md#drawing-order)

### Point Styling

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

| Name | Description
| ---- | ----
| `pointBackgroundColor` | The fill color for points.
| `pointBorderColor` | The border color for points.
| `pointBorderWidth` | The width of the point border in pixels.
| `pointHitRadius` | The pixel size of the non-displayed point that reacts to mouse events.
| `pointRadius` | The radius of the point shape. If set to 0, the point is not rendered.
| `pointRotation` | The rotation of the point in degrees.
| `pointStyle` | Style of the point. [more...](../configuration/elements#point-styles)

All these values, if `undefined`, fallback first to the dataset options then to the associated [`elements.point.*`](../configuration/elements.md#point-configuration) options.

### Line Styling

The style of the line can be controlled with the following properties:

| Name | Description
| ---- | ----
| `backgroundColor` | The line fill color.
| `borderCapStyle` | Cap style of the line. See [MDN](https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D/lineCap).
| `borderColor` | The line color.
| `borderDash` | Length and spacing of dashes. See [MDN](https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D/setLineDash).
| `borderDashOffset` | Offset for line dashes. See [MDN](https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D/lineDashOffset).
| `borderJoinStyle` | Line joint style. See [MDN](https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D/lineJoin).
| `borderWidth` | The line width (in pixels).
| `fill` | How to fill the area under the line. See [area charts](area.md).
| `tension` | Bezier curve tension of the line. Set to 0 to draw straight lines.
| `spanGaps` | If true, lines will be drawn between points with no or null data. If false, points with `null` data will create a break in the line.

If the value is `undefined`, `spanGaps` fallback to the associated [chart configuration options](#configuration-options). The rest of the values fallback to the associated [`elements.line.*`](../configuration/elements.md#line-configuration) options.

### Interactions

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

| Name | Description
| ---- | -----------
| `pointHoverBackgroundColor` | Point background color when hovered.
| `pointHoverBorderColor` | Point border color when hovered.
| `pointHoverBorderWidth` | Border width of point when hovered.
| `pointHoverRadius` | The radius of the point when hovered.

## Scale Options

The radar chart supports only a single scale. The options for this scale are defined in the `scales.r` property, which can be referenced from the [Linear Radial Axis page](../axes/radial/linear).

```javascript
options = {
    scales: {
        r: {
            angleLines: {
                display: false
            },
            suggestedMin: 50,
            suggestedMax: 100
        }
    }
};
```

## Default Options

It is common to want to apply a configuration setting to all created radar charts. The global radar chart settings are stored in `Chart.overrides.radar`. Changing the global options only affects charts created after the change. Existing charts are not changed.

## Data Structure

The `data` property of a dataset for a radar chart is specified as an array of numbers. Each point in the data array corresponds to the label at the same index.

```javascript
data: [20, 10]
```

For a radar chart, to provide context of what each point means, we include an array of strings that show around each point in the chart.

```javascript
data: {
    labels: ['Running', 'Swimming', 'Eating', 'Cycling'],
    datasets: [{
        data: [20, 10, 4, 2]
    }]
}
```

## Internal data format

`{x, y}`
