I have a crosstab report in Report Studio (modeled as a DMR in Framework Mgr) with multi columns and multirows. I need to add a new column that subtracts the values from two other columns, but only for specific rows (which are specific members from the dimension). I know the solution requires the use of the tuple function, but I cannot figure out the proper syntax.
The tuple function allows you to extract a value for a specific intersection in your dimensional model. However, the specifics of that intersection will be based on a combination of the members in the tuple function, and the context of where that expression is being evaulated. For example, if you nest "Year" and "Order Method" on the rows, and create a expression the column like: tuple([Fax],[Revenue]) Then you'll see the same value for every order method within a given year, but different values for each year. That's because we specified "Fax" (an order method) in the tuple, so it ignores the order method on the edge. We didn't specify a "year", so on any given row, the value will be given in the context of the nested year.
Now having said all that, I'm not sure I understand your requirement. You indicate that you want the column to display the difference between two other columns, but only for specific rows. What do you want to be displayed on the other rows?
