% Difference from previous week

[Yo_thescooter]

Hi all,

I have columns, country, customer, product_group, model_id, week, year, price, and sales (#). I have several countries, and each country has several product_groups, and each product_group has several model_ids. I have 52 weeks for 2021 and will continue like that for 2022, 2023 etc. Prices for model_ids differ. 

I need to find the %difference change from the previous week for each row for price and sales (#). 

Each row needs to be unique since there are several variables (country, customer, etc.) 

You can check a dummy screenshot below.

How can I do this in PowerBI? Having an extra two columns which will be like "% change price week-over-week" and "% change sales # week-over-week"

Thank you!

[mangaus1111 · Accepted solution]

Hi @Yo_thescooter ,

see my pbi file. I have splitted the column Week in 2 columns (week and year) in power query.

https://1drv.ms/u/s!Aj45jbu0mDVJi0DlD5sZpcgVxDjE?e=khhDbs

If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

[Yo_thescooter]

Hey Mangaus,

This looks promising. I will try it now. As I can see in the measure you created, you concatenated the columns to create a unique column. In that way, the calculations will be correct even if I have 1000 rows, right? 

Also, can you give me a solution for Week 1 and Week 52 issue? 

[mangaus1111]

Hi @Yo_thescooter ,

I have splitted the column [report_date_week] in 2 columns, I have not done any concatenation.

Try if it works in your model.

[Yo_thescooter]

It worked the way you did, but for the % to work, I have to have all the columns in the table, which is fine. But some tables will only have year and week, for example. And I will be looking for Avg. Price, for example. 

I tried to work on your script but couldn't manage 😕 Can you help?

I created Avg. Price measure as follows; 

Avg. Price = AVERAGE(Sheet1[Consumer Price])

[Yo_thescooter]

Let me know if anyone has any idea how to do it please

[amitchandak]

@Yo_thescooter , you need have date/week table with week rank joined to you table

Have these new columns in Date Table, Week Rank is Important in Date/Week Table
Week Start date = 'Date'[Date]+-1*WEEKDAY('Date'[Date],2)+1
Week End date = 'Date'[Date]+ 7-1*WEEKDAY('Date'[Date],2)
Week Rank = RANKX(all('Date'),'Date'[Week Start date],,ASC,Dense)
OR
Week Rank RANKX(all('Date'),'Date'[Year Week],,ASC,Dense) //YYYYWW format
WeekDay = weekday([Date])

These measures can help

This Week = CALCULATE(sum('Table'[Qty]), FILTER(ALL('Date'),'Date'[Week Rank]=max('Date'[Week Rank])))
Last Week = CALCULATE(sum('Table'[Qty]), FILTER(ALL('Date'),'Date'[Week Rank]=max('Date'[Week Rank])-1))

Time Intelligence, DATESMTD, DATESQTD, DATESYTD, Week On Week, Week Till Date, Custom Period on Period,
Custom Period till date: https://youtu.be/aU2aKbnHuWs&t=145s

Power BI — Week on Week and WTD
https://medium.com/@amitchandak.1978/power-bi-wtd-questions-time-intelligence-4-5-98c30fab69d3
https://community.powerbi.com/t5/Community-Blog/Week-Is-Not-So-Weak-WTD-Last-WTD-and-This-Week-vs-La...
https://www.youtube.com/watch?v=pnAesWxYgJ8