How to manage a progressive calculation in a Pivot table

[#1]

Hi all, I'm a qlikview newbie.

I'm facing a problem that I'm trying to solve ( see the picture).

What is the best approach to reproduce in qlikview the information displayed in the picture ?

I think that I have to use a pivot table ( in a chart control).and how to manage the 'sub totals',

But I don't have a clear idea to obtain the calculation of column 'Diff'.

note : 'Diff' values are the difference of a 'Values''s item and the previous one.

'sub totals' is the sum of the values of the column 'Diff' grouped by 'Date'

on hourly base ( the first sub total is the sum of 'Diff''s values grouped by

12/04/2014  'hour' 3, the second one , is the sum grouped by 'hour 4'. etc .. )

Could you help me ?

Thanks in advance.

Date	Values	Diff	sub totals
12/04/2014 03:35:00	12
12/04/2014 03:40:00	18	6
12/04/2014 03:45:00	19	1
12/04/2014 03:50:00	25	6
12/04/2014 03:55:00	29	4	15
12/04/2014 04:00:00	31	2
12/04/2014 04:05:00	34	3
12/04/2014 04:10:00	43	9
12/04/2014 04:15:00	45	2
12/04/2014 04:20:00	50	5	21

[Gysbert_Wassenaar]

I recommend create a date, a time and an hour field in the script. Perhaps it makes sense to calculate the Diff values in the script too. If not you can use the above() function in an expression in the pivot table. Something like sum(Values) - above(sum(Values)). If you add the hour field to the pivot table you can enable the Partial Sums option for the date dimension to get the sub totals. If you want some help with that then please post a sample document with some data.

[#3]

Thanks a lot for your answer.

I used Previous() function in the script .