To get distribution line-standard deviation in tableau to power BI

[asdf1608]

I am trying to convert the tableau dashboard to power BI.

In a line chart I need to create a distribution line with standar deviation

I am not able to understand what is factors and population in tableau.

This is the graph in tableau. The red line is the standard deviation with max

How do I create this standard deviation in power BI. I am not sure of how to create standard deviation line with factors and population in power BI

Help in this is needed.

Thanks in advance

[OwenAuger · Accepted solution]

Hi @asdf1608 

From your Tableau screenshot, Tableau is adding lines equal to the Average of the data points +/- 2 standard deviations (using Population Standard Deviation). See here.

In Power BI, it's not quite as automated, but you can produce the same result by writing appropriate measures. You would use the function STDEVX.P in this case for the population standard deviation by month.

Attached is a small example with data similar to yours.

I have a 'Date' table with column 'Date'[Year Month] which is related to the fact table's Date column.

The base measure I am using is [Sales Amount]

Average Monthly = 
CALCULATE (
    AVERAGEX ( VALUES ( 'Date'[Year Month] ), [Sales Amount] ),
    ALLSELECTED ( )
)

Standard Deviation Monthly = 
CALCULATE (
    STDEVX.P ( VALUES ( 'Date'[Year Month] ), [Sales Amount] ),
    ALLSELECTED ( )
)

Average + 2 Standard Deviations = 
[Average Monthly] + 2 * [Standard Deviation Monthly]

Average - 2 Standard Deviations = 
[Average Monthly] - 2 * [Standard Deviation Monthly]

Then add the measures as Reference lines of type Y-Axis Constant Line.

(documentation showing older version of interface).

Is this close to what you were looking for?