Compute using (table across, down) in Tableau - Cell-by-Cell Formula Trace

Sample Data

Sales data by Region and Quarter

Cell	Value
A1	Region
B1	Sales Q1
C1	Sales Q2
A2	North
B2	100
C2	150
A3	South
B3	200
C3	250

Formula Trace

WINDOW_SUM(SUM([Sales]), -FIRST(), LAST())

Step 1: SUM([Sales]) for each cell

Step 2: WINDOW_SUM(SUM([Sales]), -FIRST(), LAST()) computed across table across then down

Step 3: Assign WINDOW_SUM result to each cell

Cell Reference Map

     |  A     |  B       |  C       
-----+--------+----------+----------
  1  | Region | Sales Q1 | Sales Q2 
  2  | North  | 100      | 150      
  3  | South  | 200      | 250      

Cells B2, C2, B3, C3 contain sales values used in the WINDOW_SUM calculation

Result

     |  A     |  B       |  C       
-----+--------+----------+----------
  1  | Region | Sales Q1 | Sales Q2 
  2  | North  | 700      | 700      
  3  | South  | 700      | 700      

Each sales cell shows the total sum of all sales (700) because compute using is set to table across then down

Sheet Trace Quiz - 3 Questions

What does the WINDOW_SUM function compute in this example?

A Sum of sales only in the current column

B Sum of all sales values in the entire table

C Sum of sales only in the current row

D Average of sales values in the table

Key Result

WINDOW_SUM aggregates values over the entire table when compute using is set to table across then down