Comparative analysis

[#1]

HI folks,

I'm doing a comparative analysis which i've got working fine which uses the

sum({[ConditionB] * $} Amount)

in the expression. I have noticed though that if nothing is selected that is will sum everything rather than going to zero and having a flat or no line at all.

I thought using

sum(<${[ConditionB]}> Amount)

might work but that fails completely

Any ideas?

Thanks

[#2]

As I couldn't find an identifier here, the only option I could see was to change the import script and had the import do a sum(amount) * - 1 and tag that row onto the end.

Therefore the final summation would = 0

Not the prettiest solution