How to calculate the evolution of a given week over same week of the previous year

[#1]

Hello all

I worked with qlikview some years ago but I'm stuck with the calculation of evolution calculation

I m working with week at the following format: YYYY/WW

I prepared the following sample (which is a simplified example of the dataset I use everyday:

DATE_S	Week	Year	Week_N	Perimeter	Volume	TO
2014/10	10	2014	8	FR	3253	3643,36
2014/11	11	2014	9	FR	2535	2839,2
2014/12	12	2014	10	FR	2253	2523,36
2015/10	10	2015	60	FR	3487	3905,44
2015/11	11	2015	61	FR	2769	3101,28
2015/12	12	2015	62	FR	2487	2785,44
2014/10	10	2014	8	EN	3577	4006,24
2014/11	11	2014	9	EN	2859	3202,08
2014/12	12	2014	10	EN	2577	2886,24
2015/10	10	2015	60	EN	3811	4268,32
2015/11	11	2015	61	EN	3093	3464,16
2015/12	12	2015	62	EN	2811	3148,32

My problem is that I want to calculate and plot the evolution of Volume or TO vs previous year

I tried using a set analysis with variable Year = Year-1 or Week_N = Week_N - 52 (Week_N, is used to number the week from 2012)

In my chart X axis is DATE_S

Here below, the formulas I tried:

=sum(Volume) / Sum({$ <Year ={$(=Year-1)}> } Volume)

or

=sum(Volume) / Sum({$ <Year ={$(=vYearM1)}> } Volume) where vYearM1 = Year -1

I tried the same with Week_N - 52 .. but it doesn't work anymore,

Thanks all for your help

Jonathan

[Gysbert_Wassenaar · Accepted solution]

See attached example.

[#3]

I can't see the attached file ?

[Gysbert_Wassenaar]

I can:

Try again. If you still can't see it we'll mention the issue to the administrators.

[#5]

it's ok, I was just in my notification where I can read the answer but where I con't see Attached file. Thank you! I will look at it.