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# Polar Area
Polar area charts are similar to pie charts, but each segment has the same angle - the radius of the segment differs depending on the value.
This type of chart is often useful when we want to show a comparison data similar to a pie chart, but also show a scale of values for context.
{% chartjs %}
{
"type": "polarArea",
"data": {
"labels": [
"Red",
"Green",
"Yellow",
"Grey",
"Blue"
],
"datasets": [{
"label": "My First Dataset",
"data": [11, 16, 7, 3, 14],
"backgroundColor": [
"rgb(255, 99, 132)",
"rgb(75, 192, 192)",
"rgb(255, 205, 86)",
"rgb(201, 203, 207)",
"rgb(54, 162, 235)"
]
}]
},
}
{% endchartjs %}
## Example Usage
```javascript
new Chart(ctx, {
data: data,
type: 'polarArea',
options: options
});
```
## Dataset Properties
The following options can be included in a polar area chart dataset to configure options for that specific dataset.
| Name | Type | Description
| ---- | ---- | -----------
| `label` | `String` | The label for the dataset which appears in the legend and tooltips.
| `backgroundColor` | `Color[]` | The fill color of the arcs in the dataset. See [Colors](../general/colors.md#colors)
| `borderColor` | `Color[]` | The border color of the arcs in the dataset. See [Colors](../general/colors.md#colors)
| `borderWidth` | `Number[]` | The border width of the arcs in the dataset.
| `hoverBackgroundColor` | `Color[]` | The fill colour of the arcs when hovered.
| `hoverBorderColor` | `Color[]` | The stroke colour of the arcs when hovered.
| `hoverBorderWidth` | `Number[]` | The stroke width of the arcs when hovered.
## Config Options
These are the customisation options specific to Polar Area charts. These options are merged with the [global chart configuration options](#global-chart-configuration), and form the options of the chart.
| Name | Type | Default | Description
| ---- | ---- | ------- | -----------
| `startAngle` | `Number` | `-0.5 * Math.PI` | Starting angle to draw arcs for the first item in a dataset.
| `animation.animateRotate` | `Boolean` | `true` | If true, the chart will animate in with a rotation animation. This property is in the `options.animation` object.
| `animation.animateScale` | `Boolean` | `true` | If true, will animate scaling the chart from the center outwards.
## Default Options
We can also change these defaults values for each PolarArea type that is created, this object is available at `Chart.defaults.polarArea`. Changing the global options only affects charts created after the change. Existing charts are not changed.
For example, to configure all new polar area charts with `animateScale = false` you would do:
```javascript
Chart.defaults.polarArea.animation.animateScale = false;
```
## Data Structure
For a polar area chart, datasets need to contain an array of data points. The data points should be a number, Chart.js will total all of the numbers and calculate the relative proportion of each.
You also need to specify an array of labels so that tooltips appear correctly for each slice.
```javascript
data = {
datasets: [{
data: [10, 20, 30]
}],
// These labels appear in the legend and in the tooltips when hovering different arcs
labels: [
'Red',
'Yellow',
'Blue'
]
};
```
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