Cumulative SUM using Rank, NOT Dates

[MWinter225]

Hi All,

I've been researching a while about how to do this and I feel like I'm getting close. I'm pretty familiar with DAX but feel much more comfortable in languages used by Tableau and Spotfire.

What I'm trying to do:

1. Create a cumulative/running sum of Media cost that aggregates from the TV station that has the highest MER (a ratio where MER=Sales/Spend)and work our way down from the first highest MER station  to the second highest to the third highest … etc.
   1. Below we have a table with Station, Media Cost for that station, and MER sorted descending from the highest MER. I need to write a calculation that sums the values according to the rank of the highest MER station.

Station	Media Cost	MER (sorted desc)	Cumulative Media Cost
B	23.25	4.3	23.25 (Media Cost of station B)
D	57.97	3.45	81.22 (Media Cost of station B+D)
A	44.78	3.35	126 (Media cost of station B+D+A)
C	266.67	1.5	392.67 (Media Cost of station B+D+A+C)

What I have done so far:

1. I have created a MEASURE that dynamically ranks each station based on the highest MER in the matrix/text table:

   Ranking MER=
   MINX (
   FILTER (
   SELECTCOLUMNS (
   ALLSELECTED ( 'Rank Report' ),
   "index", 'Rank Report'[Index],
   "rank", RANKX ( ALLSELECTED ( 'Rank Report' ), 'Rank Report'[MER],,DESC, Dense )
   ),
   [index] = MAX ( 'Rank Report'[Index] )
   ),
   [rank]
   )

    

So this gives me:

Station	Client Revenue	Media Cost	MER (sorted desc)	Top Rank Measure
B	100	23.25	4.3	1
D	200	57.97	3.45	2
A	150	44.78	3.35	3
C	400	266.67	1.5	4

I thought then I could come up with some cumulative calculation to sum Media Cost but I’ve hit a wall. The closest that I’ve gotten were these calculations giving me Media Cost for the same row (these are inspired from searcing online):

Cumulative Cost =
CALCULATE(SUM('Rank Report'[Media Cost]),
                FILTER(ALL('Rank Report'[Station]),
                                [Top Rank Measure]<=100
                                )
)

 And

Cumulative Cost 2= 
CALCULATE ( 
SUM('Rank Report'[Media Cost]),
ALLSELECTED('Rank Report'[Station])
)

Either one gives me this:

Station	Client Revenue	Media Cost	MER (sorted desc)	Top Rank Measure	Cumulative Cost
B	100	23.25	4.3	1	23.25
D	200	57.97	3.45	2	57.97
A	150	44.78	3.35	3	44.78
C	400	266.67	1.5	4	266.67

At first I tried to just use the Template for a Running Total for Dates and fill in my columns but I got an error saying: 

A function 'CALCULATE' has been used in a True/False expression that is used as a table filter expression. This is not allowed.

The basic formula for a running total is:
Running Total COLUMN =
CALCULATE (
    SUM ( ‘TableName’[ColumnYouWantToAccumulate] ),
    ALL ( ‘TableName’ ),
    'TableName'[DateColumn] <= EARLIER ( 'TableName'[DateColumn] )
)

I tried replacing the dates with my Top Ranking Measure  like this:
 
Cumulative Cost=
CALCULATE (
    SUM ( 'Rank Report'[Media Cost] ),
    ALL ( 'Rank Report' ),
    [Top Rank Measure] <= EARLIER ( [Top Rank Measure] )
)

How can I get a cumulative sum starting from the top row with the highest MER and descned down keeping a running total of Media Cost?

Let me know if you need any more info. 

Thanks,

Matt

[Anonymous · Accepted solution]

Hi @MWinter225,

In your scenario, you can create a rank column instead of measure using DAX below.

RankColumn = RANKX(FILTER('Rank Report',NOT(ISBLANK('Rank Report'[MER]))),'Rank Report'[MER],,0,Dense)

Then, create the following measures.

SumCost = SUM('Rank Report'[Media Cost])
Cumulative Cost = CALCULATE([SumCost],FILTER(ALL('Rank Report'),'Rank Report'[RankColumn]<=MAX('Rank Report'[RankColumn])))

Thanks,
Lydia Zhang

[vanessa]

Hi @Anonymous

I am trying to implement something similar. I want to calculate the running sum for product sub-categories based on sales, but I have a slicer for product categories which targets a grid with data for Product sub-category and sales. The solution mentioned by you works if I have a single product category selected in the slicer. If i "Select All", the rank and cumulative sum doesn't get calculated correctly.