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JoSwinnen's avatar
JoSwinnen
Icon for Helper I rankHelper I
4 years ago
Solved

Average duration between two dates is not calculated

Hi,   I have a dataset with multiple lines for one student. For each year he is stuying at the university a line is created with his registrationdate of that year and his deregistrationdate of that...
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  • tamerj1's avatar
    tamerj1
    4 years ago

     
    actually when I saw your reply I had a 2nd look at the solution and the results. 
    In your report you are slicing by 'vw_powerBI'[stamnummer] which means that the filter context contains the table of each student and there is no need to CALCULATETABLE - ALLEXCEPT. Therefore, the VALUES ( 'vw_powerBI'[Graduated?] ) should contain all the "Yes" and "No" values for each "stamnummer". The limitation I set is: IF at least one "Yes" is available for the current student then do the calculation otherwise return blank. I see no reason why this shouldn't work.

    However this condition need to be applied inside the SUMX as well in order to limit the total average (In the column total cell) to only the students who have "Yes" in their Graduate status. 

    Study duration =
IF (
    "Yes" IN VALUES ( 'vw_powerBI'[Graduated?] ),
    AVERAGEX (
        VALUES ( 'vw_powerBI'[stamnummer] ),
        IF (
            "Yes" IN CALCULATETABLE ( VALUES ( 'vw_powerBI'[Graduated?] ) ),
            DATEDIFF (
                CALCULATE ( MIN ( 'vw_powerBI'[registrationdate] ) ),
                CALCULATE ( MAX ( 'vw_powerBI'[deregistrationdate] ) ),
                DAY
            )
        )
    )
)

     

    JoSwinnen

amitchandak's avatar
amitchandak
Icon for Super User rankSuper User
4 years ago

JoSwinnen , Try like

 

Study duration=
VAR Startdate = calculate(min('vw_powerBI'[registrationdate]),ALLEXCEPT(vw_powerBI,vw_powerBI[studentnumber]))
VAR Enddate = calculate(max('vw_powerBI'[deregistrationdate]),ALLEXCEPT(vw_powerBI,vw_powerBI[studentnumber]))
RETURN
AVERAGEX(values(vw_powerBI,vw_powerBI[studentnumber]),calculate(DATEDIFF(Startdate, Enddate,DAY)))

JoSwinnen's avatar
JoSwinnen
Icon for Helper I rankHelper I
4 years ago

Thanks for this. Now it gives for each student the correct duration but the average is not correct. 

And there is another difficulty that I'm realizing. I only want to calculate the study duration if this student has graduated. 

So there are different rows for one student and in the last year there will be 'yes' in the column 'graduated?' but in the previous rows there will be 'no'. 

 

Any advice? 

 

Thanks,

 

Jo 

  • tamerj1's avatar
    tamerj1
    Icon for Community Champion rankCommunity Champion
    4 years ago

    Hi JoSwinnen 
    Please try the following measure. Also I would really appreciate if you share more details about your visual and what columns are you slicing by in this visual.

    Study duration =
AVERAGEX (
    VALUES ( 'vw_powerBI'[studentnumber] ),
    CALCULATE (
        DATEDIFF (
            MIN ( 'vw_powerBI'[registrationdate] ),
            MAX ( 'vw_powerBI'[deregistrationdate] ),
            DAY
        )
    )
)

     

    • JoSwinnen's avatar
      JoSwinnen
      Icon for Helper I rankHelper I
      4 years ago

      Thanks. This one gives a better result. 

      The dataset looks like this:

      Studentnumber       RegistrationDate      DeregistrationDate     Graduated?

      00001                            15/09/2019               30/06/2020                No

      00001                            15/09/2020               30/06/2021                No

      00001                            15/09/2021               30/06/2022                Yes

      00002                             15/09/2020              30/06/2021                  No

      00002                             15/09/2021              30/06/2022                  No

      00003                              ...

       

      So the formula above may only work when there is one row with a yes for that student. Students who tried but did not graduated (only no's) cant be included in the calculation. 

       

      Thanks,

       

      Jo 

      • tamerj1's avatar
        tamerj1
        Icon for Community Champion rankCommunity Champion
        4 years ago

        JoSwinnen 
        Please try

         

        Study duration =
VAR Graduated =
    CALCULATETABLE (
        VALUES ( 'vw_powerBI'[Graduated?] ),
        ALLEXCEPT ( 'vw_powerBI', 'vw_powerBI'[Studentnumber] )
    )
RETURN
    AVERAGEX (
        VALUES ( 'vw_powerBI'[studentnumber] ),
        CALCULATE (
            IF (
                "Yes" IN Graduated,
                DATEDIFF (
                    MIN ( 'vw_powerBI'[registrationdate] ),
                    MAX ( 'vw_powerBI'[deregistrationdate] ),
                    DAY
                )
            )
        )
    )

        Or 

        Study duration =
VAR CurrentStudentTable =
    CALCULATETABLE (
        'vw_powerBI',
        ALLEXCEPT ( 'vw_powerBI', 'vw_powerBI'[Studentnumber] )
    )
VAR FiteredTable =
    FILTER ( CurrentStudentTable, 'vw_powerBI'[Graduated?] = "Yes" )
RETURN
    AVERAGEX (
        FiteredTable,
        DATEDIFF (
            MIN ( 'vw_powerBI'[registrationdate] ),
            MAX ( 'vw_powerBI'[deregistrationdate] ),
            DAY
        )
    )