3 Replies Latest reply on Mar 31, 2017 8:44 AM by David Li

# Help with a difference table calculation

Hello. How can I interpret this formula? ABS(ZN(SUM([ZN(SUM([Number of Records])) - LOOKUP(ZN(SUM([Number of Records])), -1))

• ###### 1. Re: Help with a difference table calculation

Tableau is saying it's invalid. Also, how do I look at table calculations in the same screen I would use for calculations?

• ###### 2. Re: Help with a difference table calculation

What's the formula supposed to accomplish?

It looks like you have SUM within a SUM - not sure you can do that, but even if you can, I don't think it accomplishes anything.

• ###### 3. Re: Help with a difference table calculation

Hi Alex, this calculation seems like it's comparing the number of records in one cell to the number of records in the previous one and returning an absolute value. But the two SUMs and the extra open bracket will cause it to fail for sure. Try this instead:

ABS(ZN(SUM([Number of Records])) - LOOKUP(ZN(SUM([Number of Records)), -1))