GEOMEAN???? :(

Hi again ecoale

Thanks for the additional explanation. It sounds like you want to see the same constant geometric mean across all years.

Try either of these measures:

Geometric Mean of Δ =
GEOMEANX ( ALLSELECTED ( ISCRITTI[AA] ), [Δ] )

or

Geometric Mean of Δ =
CALCULATE ( GEOMEANX ( VALUES ( ISCRITTI[AA] ), [Δ] ), ALLSELECTED () )

My original measure would have worked as a standalone measure on a card, but not when filtered on an individual year.

Regards,

Owen

Glad to hear it worked :)

For your N* measure you should be able to do something like this (it worked for me in a test model):

N* =
VAR y0 =
    FIRSTNONBLANK ( ALLSELECTED ( ISCRITTI[AA] ), 0 )
VAR y =
    SELECTEDVALUE ( ISCRITTI[AA] )
VAR N0 =
    CALCULATE ( COUNT ( ISCRITTI[Student_ID] ), y0 )
VAR Mg = [Mg]
RETURN
    N0 * POWER ( Mg, y - y0 )

I have used variables to make it quite clear what the components of the calculation are.

Essentially we just need to multiply the initial Student Count by Mg raised to the power of the difference between last and first years.

Regards,

Owen