rank function in a form

Summary:

The function Rank() is available in a data form, but returns #Error.

Content :

The Rank() formula allows to rank values and then sorts them ascending or descending.

This works smoothly in a Report, especially combined with conditional suppression. This way one can build a report that shows your e.g. top 10 entities for something.

A dashboard visualization needs a data form to list the values to be presented. In this form I'm showing the children of a choosen entity (user variable in my rows). As columns I'm retrieving a single period in a data column and the next column is a formula column with a