DAX Help - CrossFilter and LookUp

[Anonymous]

Community,

I am trying to return a difference using multiple tables. I need assistance with DAX for a measure that will return the correct result.

I have two tables...

Table1 where;

Test Index Number = Populated as a sequential index for that days testing

SeqID = Set of requirements for a test

Run ID = Unique ID for a grouping of SeqID and a difference in the tested parts

Ref ID = A previous or upcoming Run ID to compare data between

Table2 where;

Test Index Number = Populated as a sequential index for that days testing (Matches table1)

Data = Data collect

Tables and Relationships (tables connected by Test Index Number)

In the image below the green column would be what is looked up and the yellow column would be the difference between the two data. The yellow column is what I'm trying to replicate.

A test PBIX file can be found here.

[Anonymous]

As long as the data in the green column is connected via a relationship to Table1/Table2, then the following code should work in a calculated column:

Difference =
Table2[Data] - RELATED ( RefData[Ref Data] )

This uses the RELATED function to get the relevant value from the green column.

[Anonymous]

@Anonymous ,

I do not have the ref data as a column and am trying to create a measure for it. Any thoughts on how to replicate the ref data with a measure?

[Anonymous]

Is the ref data in another table?

Could you connect the tables by the Test Index Number?

[Anonymous]

I need to pull the ref data from the data column in the  by looking at the Ref ID.

[Anonymous]

So is the ref data calculated? If so, how would you want it to be calculated?

In the example file you posted there's no field called ref data.

[Anonymous]

@Anonymous 

The ref data would come from the data column.

The Ref ID is used to establish a comparison. 

Maybe we could think of it as we would like to compare Test Index Number 1,2 and 3, vs. Test Index Number 7,8,9

The Run ID is a way to group the Test Index Numbers.