Power BI - Variation of value by month

[powerbi_seek]

Hello guys,

I need your help please.

I have a Datetime table (full calendar), and another table related to it, with appointment data.

I need to show the variatiion of number of appoitments by Month, in a WaterFall chart.

Actually, I have a filter on a customer, who had only 2 records on October in whole 2017.

So normally, the variation in October should be +2, and in November -2, December 0.

Unfortunatly, it's not what I have, I got only +2 in october, and that's it.

So this is the formulas of my measure:

DIFF_RDV_byMONTH:=-(calculate(sum(Interaction[NbRDVbyRow]); PARALLELPERIOD(DateDim[Date];-1;MONTH))+calculate(sum(Interaction[NbRDVbyRow])))

Thanks for your help.

regards

[spuder · Accepted solution]

Hi @powerbi_seek

I tried to rebuilt your issue and for me it seems to work. 

2 things. Change both operators and (just for optic) use PREVIOUSMONTH() instead

=CALCULATE(SUM(factAppointments[Appointments]))-CALCULATE(SUM(factAppointments[Appointments]);PREVIOUSMONTH(Kalender[Date]))

But I also tried it with Parallelperiod() and it worked as well.

[powerbi_seek]

Can you please show a visual ?

[spuder]

@powerbi_seek 

looks like this

[powerbi_seek]

I got it, my issue is related to January. I made an IF statement to do that only if the month is not January. And that seems not working

[spuder]

I think this should work as well. The whole calculation should be surounded by a CALCULATE() that has a filter condition "not January"

CALCULATE([Total Appointments]-CALCULATE([Total Appointments];PREVIOUSMONTH(DateTable[Date]));DateTable[Date].[Monat]<>"Januar")

[powerbi_seek]

Hi, that's it what I did, but didn't work, till I also filtered on Non Blank date field. Thanks anyway, it's working .