Hi

I am not going try to envision what this vehicle looks like

but you are on the right track with using a lookup function but I think the logic here can is actually     that you want all three values to be the same

IF [Nb Engine running] = [Nb Engine optimal]

AND LOOKUP([Nb Engine optimal],1) = [Nb Engine running]

AND LOOKUP([Nb Engine optimal],2) = [Nb Engine running] THEN

    TRUE

ELSE

    FALSE

END

now make sure you set the calculation in the right direction based on the table and it should work

BTW  I cam to Tableau from an excel background  - and it took some work to understand the use of dimensions and measures acting like an entire column in a spreadsheet -  lookup  functions are just moving around the table that underlays the specific worksheet (as filtered)  -    in the formula above yo are working with a single record for the running engine   and then moving down ? the table to optimal engine

Jim

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good morning

the format for a lookup requires that the field be aggregated  just the way it is so all the fields in the expression must be an aggregate

lookup is a table calculation and tables are the result of bringing dimensions and measures to the canvas which creates aggregates in the process

stand back from your excel background for just a second and think about a calculation in Tableau ( or any other data base orient system) as creating a cell formula in a spreadsheet and simultaneously copying that formula to an entire column (or row) in that spreadsheet -

additionally the order of operation in tableau Table Calculations are at the bottom - makes sense - the table needs to be created and filtered before you can move around the table and select values (as with lookup) or do other calculations like running sum

Jim

If this posts assists in resolving the question, please mark it helpful or as the 'correct answer' if it resolves the question. This will help other users find the same answer/resolution.  Thank you.

if you post your book I will look at it

Jim

Nicolas,

You still need to aggregate because Tableau cannot assume that you have only one record for a given timestamp.

If you look in the attached, I have a column ID which is unique for every row. Using this I can resolve you problem with

ATTR( [Optimal] ) = ATTR( [Running] ) and LOOKUP(ATTR( [Optimal] ),1) = ATTR( [Running] ) and LOOKUP(ATTR( [Optimal] ),2) = ATTR( [Running] )

compute using Table Down (sheet 2)  or ID  if ID is the only Dimension in the View (Sheet 2(2) ).

If ID is not in the view  then I get more than one record for each  Optimal-Running group  so the computing is done based on each group  and does not resolve your problem.

Sheet 2(3)

So if your timestamp uniquely identify each row, and you have it  in the detail of the view, you can use the above formula  and adjust the  computation based on the structure of the view.

Michel

Michel is correct - and it reinforces why we like to see the actual workbook and all the other calculations that go into it

Nicolas,

You can use  [Calculation1]

ATTR( [Nb Engine theoretical optimal] ) = ATTR( [Nb engine running] ) and LOOKUP(ATTR( [Nb Engine theoretical optimal] ),1) = ATTR( [Nb engine running] ) and LOOKUP(ATTR( [Nb Engine theoretical optimal] ),2) = ATTR( [Nb engine running] )

compute using  Timestamp

If you want to show a graph, showing only the periods where the running engine was optimal, you can create another calculation

if [Calculation1] then ATTR( [Nb engine running] ) else 0 end

compute using  Timestamp

and build a graph like this

In your dataset , running engine is optimal  only on cases where running engine =1,  so the bar dont get higher than 1. Where there is no bar it is because the engine is not optimal.

Michel

Are you sure you are comparing the same measure.

It looks that you are comparing Nb of Engine Theorical Optimal   with   Nb Engine Running.

What is your formula for the calculation   Nb Engine Running.