topic Re: Getting the Previous Value in a Matrix with 7 rows in DAX Commands and Tips

Getting the Previous Value in a Matrix with 7 rows

MrHajiCoolBreez — Mon, 16 Dec 2024 18:46:11 GMT

I have a Matrix which looks like this

I have 7 Columns in ROWS
"EndOfSnapShotWeek" in the COLUMNS
and "Rev1" and "Rev2" in the VALUES

I want to create two measures that will calculate whether the "Rev1" or "Rev2" VALUES has gone up/down compared to the previous week (EndOfSnapShotWeek column.).
Then I can use that in conditional formatting.
I can handle the conditional formatting I just need help with the DAX.

Sample PBIX file is attached here
Sample PBIX

Re: Getting the Previous Value in a Matrix with 7 rows

lbendlin — Mon, 16 Dec 2024 13:54:30 GMT

use Visual Calculations - particularly PREVIOUS.

Re: Getting the Previous Value in a Matrix with 7 rows

MrHajiCoolBreez — Mon, 16 Dec 2024 15:35:31 GMT

This works to calculate the differences but I can't use those Visual Calculations Measures in the Conditional Formatting.

They don't appear in the "which field should we base these on" drop down

Re: Getting the Previous Value in a Matrix with 7 rows

lbendlin — Mon, 16 Dec 2024 15:38:55 GMT

correct, that is a know current limitation

Using visual calculations in Power BI Desktop - Power BI | Microsoft Learn

Re: Getting the Previous Value in a Matrix with 7 rows

MrHajiCoolBreez — Mon, 16 Dec 2024 15:42:20 GMT

Do you have a workaround or an alternative approach to solve my initial problem?

Re: Getting the Previous Value in a Matrix with 7 rows

lbendlin — Mon, 16 Dec 2024 17:16:57 GMT

Short of materializing your result into a calculated table? Don't think so. But worth a try.

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Please show the expected outcome based on the sample data you provided.

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Re: Getting the Previous Value in a Matrix with 7 rows

MrHajiCoolBreez — Mon, 16 Dec 2024 18:48:37 GMT

Here is a PBIX file with sample data
Sample PBIX
I don't have super user access so I can't directly attached a PBIX so I'm using WeTrasfer

With regards to expected output, if you can create 2 measures that I can use in conditional formating that shows the difference between Rev1 and Rev2 with the previous week that would be ideal

Re: Getting the Previous Value in a Matrix with 7 rows

lbendlin — Tue, 17 Dec 2024 01:26:25 GMT

You have interesting data including negative numbers. Calculating a WoW with a mix of positive and negative numbers is extremely subjective. Make sure you agree with the formula.

Here's my (subjective) version:

Rev1 change = var pr1 = CALCULATE(sum(test[Rev1]),DATEADD('Calendar'[Date],-7,DAY)) return divide(sum(test[Rev1])-pr1,abs(pr1),1)

However your x axis is driven by a fact date (end of snapshot week) and not by the dimension date as it should be . You will want to correct that too ( or modify the above formula)

Re: Getting the Previous Value in a Matrix with 7 rows

MrHajiCoolBreez — Tue, 17 Dec 2024 09:24:35 GMT

Thank you for this but the formula for `pr1` isn't quite right.
My bad, my explanation for expected output wasn't clear.

As you will notice that not every change is being highlighted as red or green.
For example, Rev1 on row 6 should be in green. Value went up from 30527.25 to 30346.50

pr1 = var eosw = max(test[EndOfSnapshotWeek]) RETURN CALCULATE( sum(test[Rev1]), test[EndOfSnapshotWeek]=eosw-7 )

I require it to match this visual calculation

vcPr1 = PREVIOUS([Rev1], 1, COLUMNS)

As you can see they don't match

My X axis is driven by the fact table because the active relationship between the fact table and the calendar table is on a different date column in the fact table.

Re: Getting the Previous Value in a Matrix with 7 rows

lbendlin — Tue, 17 Dec 2024 13:51:22 GMT

As you can see in my example I included a neutral area of +/- 5%. Feel free to modify that.

Re: Getting the Previous Value in a Matrix with 7 rows

MrHajiCoolBreez — Wed, 18 Dec 2024 09:43:32 GMT

Cool, thanks. All working now