Row level calculation over the dimention

[googlogmob]

I have to calculate measure DIFF = [PLAN]-[SUMM] over only [Type]  column for every value
and summ only values >0 

[PLAN] = SUM(tab[plan])
[SUMM] = SUM(tab[fact])

I tried use SUMMARIZECOLUMNS, but I got error "SummarizeColumns() and AddMissingItems() may not be used in this context"

DIFF = 
VAR tab = SUMMARIZECOLUMNS(crm[Type];"diff";[PLAN]-[SUMM]))
RETURN SUMX(tab;[diff])

and cant understand how to add checking 

[PLAN]-[SUMM] > 0

in this calculation 

Help please

[DAX0110 · Accepted solution]

Without having your source dataset to work with, I can only attempt a theoretical solution... have a try and see if this works:

Create a measure called "DIFF (PLAN-SUMM)" :

=VAR isInRow = HASONEVALUE( tab[Type] )

RETURN SUMX(

       VALUES( tab[Type] )

       ,  CALCULATE(

              VAR thePlan = SUM(tab[PLAN])

              VAR theSumm = SUM(tab[SUMM])

              VAR DIFF = thePlan - theSumm

              RETURN

                      IF ( DIFF >= 0, DIFF

                         , IF( isInRow, DIFF

                               , 0  )

                          )

              )

       )

This measure should work in both the grand total cell and in each row.

When it's in "row mode", all kinds of DIFF's will be displayed, but

when it's in grand total mode, only DIFF>=0 will be included.

[googlogmob]

@DAX0110, it works as it should! 🙂
Thanks very much 

[DAX0110]

You're welcome!