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MindIsBlank's avatar
MindIsBlank
Frequent Visitor
6 years ago
Solved

DAX Version of Excel's DSTDEV

New to Power BI but have some experience with Tableau.

 

Looking to add a measure that calculates the standard deviation for unique categorical values in a column. For example, Column A has a category. Column B has the values on which I need to calculate the standard deviation. I need to calculate the st dev of Column B for all unique categories of Column A. Example data below:

 

Column AColumn B
Name1204.0730158
Name27176.691379
Name3129.2877416
Name1205.8627572
Name27203.935509
Name3130.522898
Name1207.2325321
Name27231.588786
Name3130.8039379

 

Name1 st dev would use 204.0730158, 205.8627572, and 207.2325321. Name2 and Name3 st deve would follow in similar manner. Hoping to setup a measure that would do all that for me so I can use it in line charts and scatter plots.

 

Any ideas? Thanks in advance.

  • MindIsBlank's avatar
    MindIsBlank
    6 years ago

    I figured it out. Had to use nested filtering described in this article from 2012.

     

    Measure code looks like this:

     

    calculate(
         STDEV.P(Column B)
         ,FILTER(
              ALL('Table')
              ,COUNTROWS(
                   FILTER(
                        'Table'
                        ,EARLIER(Column A) = Column A
                   )
              )
         )
    )

4 Replies

  • Create a measure like below:
    SD=STDEV.P(Table[SalesAmount])

    Don't forget to give thumbs up 👍and accept this as a solution if this helps you.
  • Anonymous's avatar
    Anonymous
    Not applicable

    Measure =

    Calculate (

            STDEV.P('TableName'[ColumnB]),

            ColumnA = "Name1")

    • MindIsBlank's avatar
      MindIsBlank
      Frequent Visitor

      Yeah, I thought of that but I need it to dynamically load what goes into the CALCULATE() filter based on the row Power BI is evaluating. So it would be something like:

       

      Calculate (

              STDEV.P('TableName'[ColumnB]),

              ColumnA = {Value from Column A in row being evaluated})

       

      I just can't figure out how to tell it to do it that way. Another way I've gotten this to work in Excel is using the following formula as an array formula.

       

      =STDEV.P(IF($A$2:$A$9000=A2,$B$2:$B$9000))

      • MindIsBlank's avatar
        MindIsBlank
        Frequent Visitor

        I figured it out. Had to use nested filtering described in this article from 2012.

         

        Measure code looks like this:

         

        calculate(
             STDEV.P(Column B)
             ,FILTER(
                  ALL('Table')
                  ,COUNTROWS(
                       FILTER(
                            'Table'
                            ,EARLIER(Column A) = Column A
                       )
                  )
             )
        )