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,

• ###### 1. Re: Table calculation in data triangles.

Hi Nathan,

Would you be able to post a sample workbook (twbx file) so that I can try to troubleshoot this? Thanks!

-Tracy

• ###### 2. Re: Table calculation in data triangles.

Hi Tracy,

I look forward to hearing what you find out.

Regards,

Nathan

• ###### 3. Re: Table calculation in data triangles.

Hi Nathan,

Can you re-post the workbook, saving it as a twbx file? This will require an extract to be taken of the data, then saving it as a twbx file. Thanks!

-Tracy

• ###### 4. Re: Table calculation in data triangles.

Hi Tracy,

Here it is.  Apologies for that.

Thanks,

Nathan

• ###### 5. Re: Table calculation in data triangles.

Hi Nathan,

I have reattached your workbook with instructions on getting the desired output. This was a fun one!

-Tracy

• ###### 6. Re: Table calculation in data triangles.

Hi Tracy,

Thanks very much for this.  You were spot on.

I've seen this problem solved in much more elegant ways in other BI applications though.

Thanks again,

Nathan