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RobinW2's avatar
RobinW2
Regular Visitor
10 years ago
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Comparing Daily Trend Year On Year

Hi there,   I hope you're well.  I am new to Power BI and trying to buid a graph that would compare a daily trend for Internet traffic with a month on month comparison.    I used a DAX formula wi...
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  • v-micsh-msft's avatar
    v-micsh-msft
    9 years ago

    Hi RobinW2,

     

    According to your description, I suppose you are using the following formula to generate the Lastmonth measure?

    Comparison_before := calculate(sum('Table'[comparison]), PARALLELPERIOD('Table'[Date],-1,MONTH))

    Please take a try to switch the PARALLELPERIOD function to DATEADD, then check to see if this would make it work.

    Comparison_before := calculate(

                                              sum('Table'[comparison]),

                                              DATEADD('Table'[Date],-1,MONTH)

                                                 )

    Regards

     

RobinW2's avatar
RobinW2
Regular Visitor
9 years ago

Hi everyone,

 

Just quickly reopening this thread as I am facing a new issue with the formula that calculates YoY data.

 

The formula is as follows:

 

Sessions Prev. Year = CALCULATE(SUM('Traffic'[Sessions]), DATEADD('Traffic'[Date Right Format], -1, YEAR))

 

However, when applying filters for half a month (e.g. 01/09 to 15/09), the previous year data calculates the whole September month rather than only for this data range. 

 

Would anyone know what is causing the issue?

 

Thanks.

 

Robin.

v-micsh-msft's avatar
v-micsh-msft
Icon for Microsoft Employee rankMicrosoft Employee
9 years ago

Hi RobinW2,

Apologize for the late response. This might be related with the DATEADD function. DateAdd function only returns a single column of Datekey which overwrites existing filter on the same column.

I would try to create some tests on this, will share the results once I finished.

A blog for reference:

http://mdxdax.blogspot.sg/2011/01/dax-time-intelligence-functions.html

Regards

 

  • RobinW2's avatar
    RobinW2
    Regular Visitor
    9 years ago

    Hi Michael,

     

    I hope you're well and thanks a lot for coming back to me. I have actually fixed the answer by extending the dates after my last date on the excel file from which I pull the data. 

     

    It seems that Power BI was automatically recognising the September 2016 data as a full month (as there was no date beyond the 25/09 initially) and replicating this set up on the 2015 comparison.

     

    Thanks for your help!

     

    Robin.

    • v-micsh-msft's avatar
      v-micsh-msft
      Icon for Microsoft Employee rankMicrosoft Employee
      9 years ago

      OK。

      Thanks for sharing this.

      If any further questions when using Power BI, please feel free to post in this forum.

      Regards