Deviation of traffic

[DimaMD]

Hello Community

We have a traffic table which consist of 

- Timestamp (date)

- Id of shop

- Hours

- Entrance traffic

- Exit traffic

With mesures we counted total traffic per day, both for entrance and exit

Entrance_Shop = 
SumX( SUMMARIZE(
       'Traffic',
       'Traffic'[Timestamp],
        'Traffic'[Hour],
        'Traffic'[ID Shop.1],
        'Traffic'[ID Shop.2],
        'Traffic'[Entrance]
        ),'Traffic'[Entrance])

Exit_Shop = 
SumX( 
    SUMMARIZE(
       'Traffic',
       'Traffic'[Timestamp],
        'Traffic'[Hour],
        'Traffic'[ID Shop.1],
        'Traffic'[ID Shop.2],
        'Traffic'[Exit]
        ),'Traffic'[Exit])

As a result we have correct data of entrance and exit traffic by days.

Our task is to count deviation of traffic in a specific mathematic way.

sqrt((1550-1278)^2)+((1719-1278)^2)/2)=366

For this example i used data of 2 days 24.05.2022-25.05.2022 and the result should be as calculated abowe.

We divide this data with 2 because we selected 2 days as example. If we will choose more days, formula must divide data with quantity of choosen days. 

Our mesure that we use in PBI looks as following:

Deviation = 
VAR _AmDates = CALCULATE(COUNTROWS(DATESBETWEEN('Dates'[Date],MIN('Dates'[Date]),MAX('Dates'[Date]))))
VAR _Entrance = 
SumX( SUMMARIZE(
       'Traffic',
       'Traffic'[Timestamp],
        'Traffic'[Hour],
        'Traffic'[ID Shop.1],
        'Traffic'[ID Shop.2],
        'Traffic'[Entrance]
        ),'Traffic'[Entrance])
VAR _Exit =       
 SumX( SUMMARIZE(
       'Traffic',
       'Traffic'[Timestamp],
        'Traffic'[Hour],
        'Traffic'[ID Shop.1],
        'Traffic'[ID Shop.2],
        'Traffic'[Exit]
        ),'Traffic'[Exit])
VAR kvadrat = 
POWER( ABS( _Entrance-_Exit ), 2 ) 
Return
 DIVIDE( SQRT( kvadrat ), _AmDates)

For some reason if I try to count this in PBI I can not achieve this result. I dont know why but we get result of 356,5 instead of 366

Please help us to understand correct mesure to achieve correct result of 366

Example pbix

[DimaMD · Accepted solution]

Hello Community

After conducting research, we came to the desired result.

The first thing we did was derive a compute table that deduced the value squared.

_traffic = 
SUMMARIZE(
       'Traffic',
       'Traffic'[ID Shop.1],
       'Traffic'[Timestamp],
       "vx",
            POWER( 
                ABS( 
                    SUM('Traffic'[Entrance]) - SUM('Traffic'[Exit])),2)
        )

The second thing that was done was added dimShop and made connections between the tables



And the last stage of creating a measure, I brought the desired result

Deviation = 
VAR _AmDates = CALCULATE(COUNTROWS(DATESBETWEEN('Dates'[Date],MIN('Dates'[Date]),MAX('Dates'[Date]))))
VAR kvadrat = SUM('_traffic'[vx])
Return
 SQRT( DIVIDE( kvadrat , _AmDates))