nested set analysis

[hov]

Hi, I am new to qlik and am having some trouble with a set analysis expression im trying to handle.

I am trying to calculate the diff of a measure between the max date in the selection and its predecessor. 

date_num = integer value of my date, increasing

report name = report selection 

A region filter also applies 

I would like something as follows however this doesnt work when a single date is selected. 

count({<date_num={$(=max(date_num))}>}ReportName) - count({<date_num={$(=max(date_num, 2))}>}ReportName)

I would like to keep the other two filters to work as normal (reportname and region)

[agigliotti]

maybe this:

=date( max( {< date_num = E( date_num ) * {"<$(=Max(date_num))"} >} date_num ) )

it should works when a single date has been selected giving you the same value as Max(date_num,2).

I hope it can helps.

Best Regards

[marcus_sommer · Accepted solution]

No, it won't produce the same issue because it overwrites the set selection. Therefore, the following should work:

count({<date_num={$(=max(date_num))}>}ReportName) -
count({<date_num={$(=max(date_num)-1)},
   ReportName=p(ReportName), Region=p(Region)>}ReportName)

in regard to the above mentioned fact of the existing date_num.

- Marcus

[hov · Accepted solution]

Hi thank you for your input.

This approach worked for me, with the addition of {1} in the subtraction.

count({<date_num={$(=max(date_num))}>}ReportName) - count({1<date_num={$(=max(date_num)-2)}, ReportName=p(ReportName), Region=p(Region)>}ReportName)