SQL Cube calculate difference

Question

In my data I have own row that either says "Ist" or "Plan". This row is also defined as its own Dimension, of course again having those two fields.

Now I would like to have an own measure showing differences between Plan and Ist.

Here is what I tried in the Calculations-section of my cube:

create member currentcube.[Measures].[diff] as 0;
Scope [Measures].[diff] ;
this = iif([Plan_Ist].[Plan Ist] = [Plan_Ist].[Plan Ist].&[Ist],- [Measures].[Betrag],[Measures].[Betrag]);
end scope;

This does seem to work for the columns "Plan" and "Ist", but the Grand total of the measure diff is the same as the measure Betrag. Also if I am not having "Plan" and "Ist" visible, the measure Diff is 0.

What am I doing wrong? I am a beginner with cube-calculations (as might be obvious) and I am quite stuck...

Thx Max

Answer 1

as I did not get any answer I have choosen the way to split the data already in an view I use to get my data into the cube. So instead of getting one value and "Plan" or "Ist" in an separate column, I now get different value-columns with values for "Plan, "Ist" and "Diff"