Reference Line

Reference Line feature is available in the following chart types.

  • Bar: X-Axis, Y-Axis

  • Line: X-Axis, Y-Axis

  • Scatter (No Aggregation): X-Axis, Y-Axis

  • Scatter (With Agggregation): X-Axis, Y-Axis

  • Histogram: X-Axis

  • Density Plot: X-Axis

  • Error Bar: Y-Axis

  • Error Bar (Summarized Data): Y-Axis

Reference Line is available only when a numeric column is assigned to the target Axis.

How to Use

You can configure the Reference Line on the Reference Line dialog. You can open the Reference Line dialog by choosing 'Reference Line' menu from the Axis menu dropdown.

In the Reference Line dialog, you can select the type and style of the Reference Line.


Following Reference Line types are available.

  • (None)

  • Sum

  • Mean (Average):

  • Median

  • Mode

  • Min Value

  • Max Value

  • First: First value of the data.

  • Last: Last value of the data.

  • Diagonal: It is available in Scatter (No Aggregation and With Aggregation) and numeric columns are assigned to both X and Y.

  • Constant: Constant value that you specify.


  • Group By

    • All - Against the all data.

    • X Axis - For each X Axis.

    • Color By - For each Color By.

    • Repeat By - For each Repeat By.

    • X Axis + Repeat By - For each X Axis and Repeat By.

    • Color By + Repeat By - For each Color By and Repeat By.

  • Label - Label text that will show up in Popup and Legend.

  • Range Type - You can show the value distribution range. Only available for 'Mean' and 'Median' Reference Line types.

    • (None)

    • Standard Error

    • 90% Conf. Interval

    • 95% Conf. Interval

    • 99% Conf. Interval

    • 1 Standard Deviation

    • 2 Standard Deviation

    • 3 Standard Deviation

    • IQR

  • Show in Legend - Check if you want to show the Reference Line item in the Legend.

  • Color

  • Line Width: Thickless of the line.

  • Line Length

  • Line Style

    • Solid

    • Dot

    • Dash

    • Long Dash

    • Dash and Dot

    • Long Dash and Dot

Drawing Multiple Constant Reference Lines

You can render multiple Reference Lines in "Constant" Reference Line type. You can set multiple values separated by comma at "Constant Values". You can also define multiple labels separated by comma at "Constant Label".

Numeric Axis Example

Date Axis Example

Showig Reference Line Labels on Plot Area

You can show the Reference Line labels and values on the plot area. You can change the setting at "Show Text on Plot Area" in the Reference Line dialog.

The following options are available.

  • None

  • Label Only

  • Label and Value

Currently, "Show Text on Plot Area" option is available only for the vertical (X-Axis) Reference Lines.