Add an auxiliary line to your chart:

1. On the chart definition panel, go to the Lines tab. Several line definition options are available.

2. (Optional) Enter a line Label for easy identification in the chart.

3. Enable the Show in legend option if you want to include the label in the chart legend.

4. Enable the Show data labels option, if you want to display the values of the variables in the chart.

5. Select the desired Line Type from the drop-down menu:

   • Line

   • Stepped Line

   • Vertical Line

6. Define the line properties.

7. Click the Refresh button to update the chart and see the line(s).

8. Repeat the process until you have defined all auxiliary lines.
   You can remove a line by clicking the X icon. The chart will be refreshed automatically.

Line

Define the Line type:

1. Select a color from the drop-down list.

2. Define the Y Intercept. Enter a value or click the icon to define a simple formula. You can use the Visual Editor or the standard script editor.

3. Define the slope of the auxiliary line in the Steepness field. Enter a value or click the icon to define a simple formula. The slope is zero by default.

The functions available in the formula builder include LRa, LRb and ERa, ERb. These functions run a linear or exponential regression on the data set in the query result. The LR coefficients are added to the query's Summary map. The coefficient for the given independent variable is in summary.projections.<alias>.LRb (or ERb for the exponential regression). The intersect on the dependent variable axis is in summary.projections.<alias>.LRa (ERa). BinW performs data binning and calculates the bin width.

Stepped Line

Define the Stepped Line type:

1. Select a color from the drop-down list.

2. Click Add Coordinates (Step) and for each step enter the X and Y value.
   The X coordinates can be provided as double-quoted strings, using the same format as the chart's X axis.
   For example, if it is a daily chart, then "2017-07-13", if it is weekly "2017-W27", and so on with "2017-M07", "2017-Q3" or just "2017".

Vertical Line

Define the Vertical Line type:

1. Select a color from the drop-down list.

2. Define the X Intercept. Enter a value (for details on the format see Stepped Line) or a simple formula (in the Formula Builder window).

How to Define Auxiliary Line Using Calculation Logic

You can use an Analytics logic to define the values of the X and Y Intercepts and Steepness.

On the Logic tab, select the logic you want to use from the drop-down list.

Open

Once the logic is executed the summary outputs are available in the Formula Builder Series menu for X and Y Intercept and Steepness fields. When the chart is refreshed, auxiliary lines corresponding to the logic output are rendered.

For more information, see Analytics Calculation Logic.

Note: In the current version, only the Summary output is supported (not the row-level output).