By default, null values do not appear in chart widgets. If, for example, a user creates a chart showing sales for each day of the week, days for which there were no sales would be omitted from the X axis.
Users looking to include null values in their charts can work around this limitation by using Chart Layout One. Chart Layout One allows the user to define each point in a chart whereas Layout Two and Layout Three infer the data structure from the report's design.
To ensure that a chart displays null values, set up your report so that each point in the chart has a unique cell corresponding to that point's X and Y values. Below is how one might do this using the day-of-week sales report example. Each X value (day of the week) has its own cell, and each Y value (number of sales) also has its own cell.
Note: This example uses the DayOfWeek custom function. See this article for instructions on how to implement it in your environment.
Once the report data has been set up, the user can add a chart to the report footer, select Data Layout One on the Data tab, and begin assigning each point its X and Y values.
This method will produce output including a point for "Monday," even though its Y value is null.