DAX Version of Excel's DSTDEV

[MindIsBlank]

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 A	Column B
Name1	204.0730158
Name2	7176.691379
Name3	129.2877416
Name1	205.8627572
Name2	7203.935509
Name3	130.522898
Name1	207.2325321
Name2	7231.588786
Name3	130.8039379

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.

[Anonymous]

Measure =

Calculate (

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

        ColumnA = "Name1")

[MindIsBlank]

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 · Accepted solution]

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
               )
          )
     )
)

[Tahreem24]

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.