topic Re: Need help in understanding the Expression..? in QlikView

Need help in understanding the Expression..?

Wed, 21 May 2014 06:48:16 GMT

Hi all,

I have seen on e expression, which is like : Sum(-(Amnt>0)*Amnt)

Why we have to write like this , what is the need , since we have got Amnt already in expression.

why we have to use sum(-(Amnt>0)) extra..

Thanks...

Re: Need help in understanding the Expression..?

tresB — Wed, 21 May 2014 06:53:19 GMT

Amnt>0 returns -1 (True) or 0 (False). Hence Sum(-(Amnt>0)) sums -(-1) (i.e. 1) for values of Amnt greater than zero. Hence the entire expression is actually equivalent to Sum(If(Amnt>0, Amnt,0)).

Re: Need help in understanding the Expression..?

alexandros17 — Wed, 21 May 2014 06:54:38 GMT

Sum(-(Amnt>0)*Amnt)

If Amnt>0 is true then the expression become: Sum(-(-1)*Amnt) that is Sum(Amnt)

If amnt>0 is false then Sum(-(0)*Amnt) that is 0

We are summing only positive values for amount

Re: Need help in understanding the Expression..?

struniger — Wed, 21 May 2014 06:54:54 GMT

This will give you a value of decimal zero when you have a negative figure in Amnt, thus only summing up positive values.

The expression (Amnt>0) will either return True (-1) or False (0)

Hope this helps to clear up your question.

Best regards

Stefan

Re: Need help in understanding the Expression..?

Wed, 21 May 2014 06:56:27 GMT

Hi tresesco,

Thanks for your reply, that is ok but.. why we have to use this Sum(-(Amnt>0)), instaed directly we can use

Sum(Amnt) rt..?

Re: Need help in understanding the Expression..?

tresB — Wed, 21 May 2014 06:59:23 GMT

If you have negative values in Amnt, they would not be summed. Sum(Amnt) - sums all irrespective of if Amnt is positive or negative. Hope this helps.