Overview
The Line chart is a cartesian chart type within the Chart block. It plots one line per series across an X axis, with the richest per-series styling of any chart type — including line width, dash pattern, shape (linear vs spline), area fill below the line, and point markers. An area chart is simply a Line chart with the Fill under line option enabled on one or more series.
Tip: Set Chart Type to Line and set Fill under line to Gradient or Solid on one or more series to create an area chart. A chart with one series and no Group by starts with Gradient; with more than one series or a Group by, new series start with None.
X Axis Configuration
Line shares the same X-axis machinery as Bar and Column:
Property | Where to Set | Description |
|---|---|---|
Value | Content → X Axis → Value | The field plotted on the X axis. Replaced by Start value and End value when Plot Periodic Values is on. |
Label | Content → X Axis → Label | Axis caption. |
Type (scale) | Content → X Axis → Type | Linear (default) for numbers, Time for dates and timestamps, or Category for text values with equal spacing. Forecast needs Time. Shown only when Plot Periodic Values is off. |
Plot Periodic Values | Content → X Axis → Plot Periodic Values | A toggle. When on, each point covers a period: map a Start value and an End value field instead of Value, and the tick labels use a period format (default |
Group by | Content → X Axis → Group by | Optional. Splits the series into one line per distinct value of the chosen field. Offered only while the Y Axis has a single series. |
Y Axis
Line offers Y-axis domain (Min Value / Max Value) in addition to the standard label, tick format, and series list.
Property | Where to Set | Description |
|---|---|---|
Label | Content → Y Axis → Label | Y-axis caption. |
Tick labels | Content → Y Axis | Value format: Number, Percent, Currency, or Duration. Compact notation available for Number and Currency. |
Min Value / Max Value | Content → Y Axis → Min Value / Max Value | Fixed bounds for the Y axis. Leave them empty (Auto) to fit the axis to the data. |
Series | Content → Y Axis → Series | One or more series. Manual or Mapped mode. |
Per-Series Line Styling
Each series on a Line chart has a rich set of appearance options, accessed through the series detail panel:
Property | Default | Description |
|---|---|---|
Line width | 1 | Stroke width of the line. |
Line dash | Solid | Line style: Solid, Dashed or Dotted. |
Line shape | Spline on a Time X axis, Linear otherwise | Linear connects points with straight segments. Spline smooths the curve between points. |
Fill under line | Gradient for a single series with no Group by; None otherwise | Gradient, Solid or None. Gradient or Solid colours the area under the line, which turns the line into an area chart. |
Point Markers | On | Shows a marker on each point. When on, set Symbol (Circle, Square, Diamond or Cross; default Circle), Size, Fill color, Border width (default 2) and Border color. |
Forecast
Plot the tail of a line in a different style to mark projected values. The Forecast settings appear in the series detail panel only when X Axis → Type is Time.
Property | Where to Set | Description |
|---|---|---|
Forecast (toggle) | Series detail panel → Forecast | Turns on forecast styling for this series. Off by default. |
Forecast From | Series detail panel → Forecast From | A date. Every point on or after this date is drawn as forecast. The boundary point is drawn in both segments, so the line does not break. |
Pattern | Series detail panel → Pattern | Dashed (default) or Dotted. |
Colours | Series detail panel → Forecast Line Color, Fill Color, Border color | The forecast line colour and the colours of the forecast point markers. |
Warning: Forecast works only on a Time X axis. If you change the axis Type to Linear or Category, the Forecast settings disappear and the series draws as one line.
Common Properties
Property | Where to Set | Description |
|---|---|---|
Tooltip | Content → Tooltip | Custom header and body text for the hover tooltip. |
Summary | Content → Summary | A row of formatted KPIs rendered with the chart. |
Legends (add-on) | Content → Add ons | Offered when the chart has more than one series or a Group by. Legend Position: Top Left, Top Right, Bottom Left, Bottom Right, Left or Right. |
Threshold (add-on) | Content → Add ons | A reference line at a single value or a min–max band. |
Scroller / Range Slider (add-on) | Content → Add ons | Pan and zoom the X axis. Labelled Range Slider on time/linear axes with configurable initial visible region. |
Chart Colours | Appearance → Chart Colours | Color assignment per series, by group values, or by conditions. |
Data Labels (per series) | Series detail panel → Data Labels | Prints the value on each point. Not available when Group by is set. Line labels have no position setting; you can add a start or end icon and style the text. |
Events
| Event | Description |
| On Data Point Click | Fires when user clicks a data point. Payload is the clicked record (all fields). |
Behavior & Gotchas
⚠ Missing dates in time-series data
The chart plots only the rows supplied by the bound data. A missing date (no row for that X value) has no point, so the line runs straight from the previous point to the next one. To show zero for that date, add a row with the value 0.
⚠ Null, missing, or non-numeric series values
A null, undefined or non-numeric series value is plotted as 0, so the line drops to zero at that point instead of breaking. Filter out or fill those rows in your data source if a drop to zero would mislead readers.
⚠ Duplicate X-axis values
Aggregate your data so each X-axis value appears once per series. If several rows share the same X value, sum or average them in your data source before binding.
⚠ Group by and multiple series
Group by and multiple series don't combine. The Group by field is offered only while the Y Axis has one series. Use Group by to split one measure into a line per group, or add several series to compare different measures.
⚠ Data labels on Line
Data labels are available on each series as long as no Group by is set. Line labels have no position setting.
Common Patterns
Multi-Series Trend Comparison
Set up Line chart with time axis: Set Chart Type to Line and X Axis → Type to Time. Bind a date field to X Axis Value.
Add multiple series: Add one series per metric (e.g., revenue, cost, profit). Each becomes its own line.
Style lines distinctly: In each series detail panel, vary Line dash (Solid / Dashed / Dotted) or the Point Markers Symbol (Circle / Square / Diamond / Cross) to tell them apart without relying only on colour.
Overlapping Area Chart
Configure Line chart with multiple series: Add one series per category. Set Line shape to Spline for a smooth look.
Enable area fill: In each series detail panel, set Fill under line to Solid or Gradient. The fills overlap rather than stack, so choose light colours in Chart Colours.
Actuals with a Forecast Tail
Set X-axis to time: Set X Axis → Type to Time — required for forecast.
Enable forecast on the series: Keep actuals and forecast in one series. In the series detail panel, turn on Forecast and set Forecast From to the date where projected values begin.
Style the forecast segment: Keep the default Dashed pattern (or choose Dotted) and set a muted Forecast Line Color so the projection reads as secondary to actuals.
Plotting a Continuous Equation
Use linear X axis: Set X Axis → Type to Linear.
Sample your equation into data: Generate an array of
{x, y}points in a run script or computed variable — the chart only plots rows you bind; there is no formula input.Smooth the curve: Set Line shape to Spline and sample more points for a smoother result.
Related Pages
Page | Relationship |
|---|---|
Shares cartesian axis and series configuration | |
Value labels on line points | |
Point-based distribution plots on the same cartesian axes |