Time comparison and line charts

[mpcbto1]

Hello,

I've read many posts in this forum but did not find one answering my question.

I have a data model with a DimDate table (days from 01.2018 to today) and another table with Traffic (Google Analytics users) data, on a day basis. Both tables are connected in the data model (via the date dimension).

I have a slicer to allow report users to filter on dates.

I created a measure to calculate the traffic of the previous period. I don't use timeintelligence functions because I want the users to be able to select a custom date range (e.g 04/30 to 06/08 as shown above).

Var_Users =

VAR date_range = COUNTA(DimDate[Date])
VAR sum_prevperiod = IF(
date_range=0,0,
CALCULATE(SUM('Raw_Data'[Users]),dateadd(DimDate[Date],-date_range+1,DAY))
)

return sum_prevperiod 

This works perfectly fine for "card" or "KPI" visuals for instance: the data displayed is the one from the previous period.

But I'd like to have a line chart comparing the data between the selected period and the previous period.

The issue is: The visual merges both lines into one, showing the same data.

Do you guys have any idea on how I can overcome this?

Thanks!

[amitchandak]

@mpcbto1 , The information you have provided is not making the problem clear to me. Can you please explain with an example.
Check if this blog can help

https://community.powerbi.com/t5/Community-Blog/Comparing-Data-Across-Date-Ranges/ba-p/823601
Appreciate your Kudos.

[mpcbto1]

Hello @amitchandak

Thanks for the reply.

I would like to be able to compare the Traffic data between two time periods: the current time period (selected in the slicer shown in my initial post) and the previous time period.

For instance : comparing Traffic data of 04/30/2020-06/08/2020 to 04/29/2020-03/21/2020.

To do this, I have created the measure shown in the initial posts, using DATEADD. This measure works very well when I use "KPI" or "cards" visuals, to show total data (Current period total traffic and Previous period total traffic).

However, I would like to show the variation of Traffic day over day in a Line Chart, and compare it to the previous period.

I would then get a line chart with:

- X axis: days (04/30/2020-06/08/2020 in my example)

- Y axis: Traffic

- 2 lines: traffic of current period (red value in the screenshot) and traffic of previous period (light red value in the screenshot).

- 2 doted trendlines for the current period and previous period

But that does not work, as shown in the screenshot, PowerBi merges both lines into one: apparently the measure I've created does not work for this kind of visualization.

I hope this makes more sense to you!

Thanks again