This article describes how to go from a crosstab with a time series variable...
...to a table with a lagged rolling average:
Requirements
- A table with a date/time variable in either the rows or columns
Method
- Select your table.
- In the toolbar, go to Automate > Browse Online Library > Modify Whole Table or Plot > 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.