How do you compute a period over period change on a data series?

[jleefjcapital]

Hello,

I just loaded GDP data, but would like to view it as a $ change over time.   How do I create such a measure?

Thank you,

Jessica

[Gysbert_Wassenaar · Accepted solution]

Well, usually you take the value of the current period and divide it by the value of the previous period and then subtract 1 from the result. Optionally you can format that result to show it as a percentage. Suppose you have MonthYear as dimension and the measure name is GDP_Amount. Your expression could be num(sum(GDP_Amount)/above(sum(GDP_Amount)) -1,'#.0%')

[jleefjcapital]

Thank you.  This was very helpful.   Is there a function directory somewhere?   How did you know to use this expression? 

[jleefjcapital]

It didn't work.   There are no values created.  

[Gysbert_Wassenaar]

Please post a qlikview document that demonstrates the problem.

[jleefjcapital]

I'm not sure how to do that....I'm very new to this. 

[Gysbert_Wassenaar]

See this document: Preparing examples for Upload - Reduction and Data Scrambling

[jleefjcapital]

I clicked on the menu in the workbook and this is what I get.   I don't see the File->Reduce Data ->Keep Possible Values as options.   I'm wondering if I'm looking in the right place. 

[jleefjcapital]

Actually, it worked.  I needed to add brackets around the series.     Thank you!

[jleefjcapital]

Ok, it works in a line graph, but not in a KPI-  this is what I get.