average x -13 months

[Anonymous]

Hello All, 

I need to create a combined graph with as target line the average count of one field per month:
I have 2 columns DATA,ID_VENDITA

The graph must have as x=MONTH(DATA) value of the graph=COUNT(ID_VENDITA) and VALUES ROW=AVERAGE(COUNT(ID_VENDITA) by MONTH of the previous -13 months

example in December as row value i should have the avg of the count(id_vendita) of the previous 13 months since November 2020 to October 2019

How can i do it? thank you very much

[amitchandak]

@Anonymous , try with a date table

Example

Rolling 13 = CALCULATE(Average(Sales[Sales Amount]),DATESINPERIOD('Date'[Date],ENDOFMONTH(Sales[Sales Date]),-13,MONTH))
Rolling 13 = CALCULATE(Average(Sales[Sales Amount]),DATESINPERIOD('Date'[Date ],MAX(Sales[Sales Date]),-13,MONTH))

Rolling 13 till last month = CALCULATE(sum(Sales[Sales Amount]),DATESINPERIOD('Date'[Date],ENDOFMONTH(dateadd(Sales[Sales Date],-1,month)),-13,MONTH))

Rolling 13 = CALCULATE(Average(Sales[Sales Amount]),DATESINPERIOD('Date'[Date ],EOMONTH(MAX(Sales[Sales Date])-1),-13,MONTH))

[Anonymous]

@amitchandak 

Thanks for the answear maybe my question was not really close to the necessity.

i try to explain better: in my file i have the following column:

DATE_OF_SALES   |  ID_SHIPMENT

what i need is to calculate the Average for every month about the avg( of the count of the ID_SHIPMENT performed in the previous .

i need to have it : consider one thing the count of the ID_RICHIESTA/month doesn't exist in the data.

Mese	Conteggio di [ID_RICHIESTA]	avg previous 13 months
gennaio	2848	2848
febbraio	2870	2848
marzo	2563	2859
aprile	2192	2760
maggio	2880	2618
giugno	8887	2671
luglio	3792	3707
agosto	8873	3719
settembre	1440	4363
ottobre	1582	4038
novembre	1334	3793
dicembre	1140	3569

[Anonymous]

@amitchandak 

 maybe thw question is differen, i need to have the average of the previous 13 month since today .

The average need to be calculate based on the count of the column ID (ID column is a text column)

the goal is to answer at the question: what is the average of the number of intervent done in the previous 13 month since today?

How can i do it? 

thank you very much