0 Replies Latest reply: Oct 5, 2015 12:05 PM by Olivier Buchy RSS

    Detect negative variations

    Olivier Buchy

      This question has probably more to do with basic stats than Qlikview per se...


      Let's say my data is the daily sales of my sales rep.


      (Date, Sales Rep Id, Amount)


      I want to be able to detect the sales rep with the biggest increase (or decrease) over a period of time (over the last week, last month, last quarter, etc.)


      My first approach is using stdev()

           Dimension : Sales Rep Id

           Expression : stdev({$<Date={">=/some reference date/"}>} Amount)

      sorting by this Expression gives me seemingly those with the biggest variation



      -stdev() is always positive, is there another function that would give the "sign"? (to distinguish overall big increases and decreases over the period?)

      -stdev() can be huge if there is one single date with a huge increase or decrease, but I'd rather identify a increasing (or decreasing) trend (and kind of ignore spikes)... anything better than stdev() for that?


      Thanks in advance