The linear scale is use to chart numerical data. As the name suggests, linear interpolation is used to determine where a value lies in relation the center of the axis.
The following additional configuration options are provided by the radial linear scale.
## Configuration Options
The axis has configuration properties for ticks, angle lines (line that appear in a radar chart outward from the center), pointLabels (labels around the edge in a radar chart). The following sections define each of the properties in those sections.
| Name | Type | Description
| ---- | ---- | -----------
| `angleLines` | `Object` | Angle line configuration. [more...](#angle-line-options)
| `gridLines` | `Object` | Grid line configuration. [more...](../styling.md#grid-line-configuration)
| `pointLabels` | `Object` | Point label configuration. [more...](#point-label-options)
The following options are provided by the linear scale. They are all located in the `ticks` sub options. The [common tick configuration](../styling.md#tick-configuration) options are supported by this axis.
The `suggestedMax` and `suggestedMin` settings only change the data values that are used to scale the axis. These are useful for extending the range of the axis while maintaining the auto fit behaviour.
let minDataValue = Math.min(mostNegativeValue, options.ticks.suggestedMin);
let maxDataValue = Math.max(mostPositiveValue, options.ticks.suggestedMax);
```
In this example, the largest positive value is 50, but the data maximum is expanded out to 100. However, because the lowest data value is below the `suggestedMin` setting, it is ignored.
In contrast to the `suggested*` settings, the `min` and `max` settings set explicit ends to the axes. When these are set, some data points may not be visible.
## Step Size
If set, the scale ticks will be enumerated by multiple of stepSize, having one tick per increment. If not set, the ticks are labeled automatically using the nice numbers algorithm.
This example sets up a chart with a y axis that creates ticks at `0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5`.
```javascript
let options = {
scales: {
yAxes: [{
ticks: {
max: 5,
min: 0,
stepSize: 0.5
}
}]
}
};
```
## Angle Line Options
The following options are used to configure angled lines that radiate from the center of the chart to the point labels. They can be found in the `angleLines` sub options. Note that these options only apply if `angleLines.display` is true.
| Name | Type | Default | Description
| -----| ---- | --------| -----------
| `display` | `Boolean` | `true` | if true, angle lines are shown
The following options are used to configure the point labels that are shown on the perimeter of the scale. They can be found in the `pointLabels` sub options. Note that these options only apply if `pointLabels.display` is true.
| Name | Type | Default | Description
| -----| ---- | --------| -----------
| `callback` | `Function` | | Callback function to transform data labels to point labels. The default implementation simply returns the current string.