This article describes how to go from a crosstab with a Date/Time variable set...
...to a table or visualization with a lagged rolling (aka smoothing or moving) average:
Requirements
- A table or visualization with a Date/Time variable.
Note: You must apply the rule directly to the input table if you see a table icon in the Data > Data Source > Data field in the object inspector of a visualization.
You will also see a warning in the Rules section of the object inspector if you have applied a rule directly to a non-compatible visualization, and you will need to apply it to the input table instead. For example:
Method
- Select your table or visualization.
- Go to Data > Rules in the object inspector.
- Select Plus (+) > Cell Content > Replace Value with Rolling Average.
- Set the Number of periods to roll.
- OPTIONAL: Tick Dates are in the rows if applicable.
- Press OK.
Please note the following:
- A lagged rolling average is computed. For example, if January has a score of 3, February 4, and March 6, the 3-period rolling average for March is (3 + 4 + 6) / 3 = 4.33333333.
- Where values cannot be computed due to insufficient data, the value is shown as NaN. For example, if January has a score of 3, February 4, and March 6, the 3-period rolling average for the three months, respectively, are NaN, NaN, and 4.33333333.
- This rule is only applied to the first statistic selected in each of Statistics > Cells and whichever is appropriate of Statistics > Below and Statistics > Right.
- You may not have a NET in the variable containing the dates.
- The statistical testing results in the table are not changed by this rule. That is, they reflect the results for the original, unrolled statistics.