The following options can be included in a line chart dataset to configure options for that specific dataset.
All point* properties can be specified as an array. If these are set to an array value, the first value applies to the first point, the second value to the second point, and so on.
lineTension | `Number` | Bezier curve tension of the line. Set to 0 to draw straightlines. *Note* This was renamed from 'tension' but the old name still works.
borderCapStyle | `String` | Cap style of the line. See [MDN](https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D/lineCap)
borderDash | `Array<Number>` | Length and spacing of dashes. See [MDN](https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D/setLineDash)
borderDashOffset | `Number` | Offset for line dashes. See [MDN](https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D/lineDashOffset)
borderJoinStyle | `String` | Line joint style. See [MDN](https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D/lineJoin)
pointBorderColor | `Color or Array<Color>` | The border color for points.
pointBackgroundColor | `Color or Array<Color>` | The fill color for points
pointBorderWidth | `Number or Array<Number>` | The width of the point border in pixels
pointRadius | `Number or Array<Number>` | The radius of the point shape. If set to 0, nothing is rendered.
pointHoverRadius | `Number or Array<Number>` | The radius of the point when hovered
pointHitRadius | `Number or Array<Number>` | The pixel size of the non-displayed point that reacts to mouse events
pointHoverBackgroundColor | `Color or Array<Color>` | Point background color when hovered
pointHoverBorderColor | `Color or Array<Color>` | Point border color when hovered
pointHoverBorderWidth | `Number or Array<Number>` | Border width of point when hovered
pointStyle | `String, Array<String>, Image, Array<Image>` | The style of point. Options are 'circle', 'triangle', 'rect', 'rectRot', 'cross', 'crossRot', 'star', 'line', and 'dash'. If the option is an image, that image is drawn on the canvas using `drawImage`.
The line chart usually requires an array of labels. This labels are shown on the X axis. There must be one label for each data point. More labels than datapoints are allowed, in which case the line ends at the last data point.
The data for line charts is broken up into an array of datasets. Each dataset has a colour for the fill, a colour for the line and colours for the points and strokes of the points. These colours are strings just like CSS. You can use RGBA, RGB, HEX or HSL notation.
The label key on each dataset is optional, and can be used when generating a scale for the chart.
The data passed to the chart can be passed in two formats. The most common method is to pass the data array as an array of numbers. In this case, the `data.labels` array must be specified and must contain a label for each point or, in the case of labels to be displayed over multiple lines an array of labels (one for each line) i.e `[["June","2015"], "July"]`.
The alternate is used for sparse datasets. Data is specified using an object containing `x` and `y` properties. This is used for scatter charts as documented below.
### Scatter Line Charts
Scatter line charts can be created by changing the X axis to a linear axis. To use a scatter chart, data must be passed as objects containing X and Y properties. The example below creates a scatter chart with 3 points.
These are the customisation options specific to Line charts. These options are merged with the [global chart configuration options](#chart-configuration-global-configuration), and form the options of the chart.
For example, we could have a line chart display without an X axis by doing the following. The config merge is smart enough to handle arrays so that you do not need to specify all axis settings to change one thing.