6 Replies Latest reply on May 24, 2012 9:05 AM by nathan.hadfield

    Table calculation in data triangles.

      Hi!

       

      We produce triangles of data that plots the number people who install our apps on a given day and then continue to use them on subsequent days.  So, if you look on the attachment, you should be able to see the pattern of data this produces where the 'Install Date' is in the columns, the 'Day' of use is in the rows and the values represent the number of users.

       

      What I need to do is create a calculation that compares the number of users on each Day to the numbers of users who originally installed the app on a given Install Date.  So, looking at the first column the ratios would be :

       

      18/05 - 100%   calculated as (84,868 / 84,868)

      19/05 - 28.7%  calculated as (24,378 / 84,868)

      20/05 - 22.4%  calculated as (19,008 / 84,868)

       

      Does anyone know a way of producing this calculation, bearing mind that we cannot use the FIRST function since on different Install Dates this value is NULL?

       

      Many thanks,

       

      NathanUser Installs.PNG