Simple calculation: No value?

[#1]

I've just started experimenting with QV. I added a simple gross margin calculation (JanProfit/JanRev) and ended up with a lot of null values (or whatever a minus means).

Any help would be greatly appreciated.

RG

[m_woolf · Accepted solution]

How about:

Sum(JanProfit)/Sum(JanRev)

[#3]

That did it. Can you explain why however?

[#4]

You need to tell it what to aggregate that's all. Do you want to sum your measure, count, count distinct etc? Because you could do count(JanProfit)/Count(JanRev) as well and it would intuitively produce different results.

I'm no expert however.