Value Average returning incorrect average when filtering?

ibtisamyyy
ibtisamyyy ⚪️
in Card Building

Hi,


So I am having a really weird issue with domo. I have a data set with 2662 rows and am trying to average let's say a column called marks for these students.

I have created a column called percentile ranking which I created using ETL where I can see how high or low the mark is in that data set.


When I create a single value card to show the average of the whole data set the average is correct.

However when I filter out the highest 10% marks (so I filter to show percentile over and equal to 0.1) the average is incorrect. Bear in mind I have 0 values before the filtering and after so that should not be affecting the average.


Do you know why it is not showing me the right average? I have tried using beast mode for the average, as well as just column value average in single value card, same issue. Tried doing sum/count of column still same issue.


Thanks!

Answers

  • amehdad
    amehdad 🔵

    Hi @ibtisamyyy, could you please share your calculations for that 'Percentile Ranking'?

  • ibtisamyyy
    ibtisamyyy ⚪️
    edited December 2021

    Hi,


    I used rank and window with a group by after to get the ranking of that data set. I divided the rank by highest rank to get the % of the rows. So example is mark 0 then % = 1 , Mark 7 then % 0.4 Mark 8 then % 0.2 etc... the higher the number the smaller the percentage. I was trying to get rid of the highest marks as they are outliers.

  • ibtisamyyy
    ibtisamyyy ⚪️

    Works now, had some null values I was not aware of that were affecting the calculations for some reason. IFNULL solved it.

  • amehdad
    amehdad 🔵

    Nice! Yeah typically nulls are ignored when calculating averages but I guess with your usecase with the Rank and Window function etc, Domo didn't know how to handle the blank values.

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