I am a beginner in timeseries, I have two datatables with different dates and i'd like to have one datatable with all the dates and the sum of the quantitative value ( money paied by the company), for example I have :
here is the first datatable with the price paied
and i'd like to have this one :
date old_price new_price
02/03/2015 1,7+1,2 5,7+1,7
05/05/2015 5,7+1,7 5,7+2,5
20/08/2015 5,7+2,5 2,3+2,5
08/09/2015 2,3+2,5 2,3+4,7
Thank you very much for your help !