topic Re: Need Help on Autocorrelation Calculation in DAX Commands and Tips

Need Help on Autocorrelation Calculation

Irwan — Thu, 14 Dec 2023 00:13:12 GMT

Hello Power BI expert,

I need an advice on how to do autocorrelation calculation in Power BI.

for now i am trying to replicate the result from excel tutorial.

I read there are two ways of calculation autocorrelation:

1. Using OFFSET and DEVSQ

2. Using VAR.P

Here is the website link that i currently work on to replicate the result How to Calculate Autocorrelation in Excel - Sheetaki

Is it possible to re-create what the excel did in Power BI? I tried to make it myself but the result is different.

Thank you and really appreciate for the help.

Re: Need Help on Autocorrelation Calculation

lbendlin — Sat, 16 Dec 2023 23:30:10 GMT

Most likelky not. Power BI has no memory and no concept of self-referencing without becoming all upset about circular references.

Please provide sample data that covers your issue or question completely, in a usable format (not as a screenshot).

Do not include sensitive information or anything not related to the issue or question.

If you are unsure how to upload data please refer to https://community.fabric.microsoft.com/t5/Community-Blog/How-to-provide-sample-data-in-the-Power-BI-Forum/ba-p/963216

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

Want faster answers? https://community.fabric.microsoft.com/t5/Desktop/How-to-Get-Your-Question-Answered-Quickly/m-p/1447523

Re: Need Help on Autocorrelation Calculation

Irwan — Sun, 17 Dec 2023 00:43:46 GMT

Hello lbendlin

here is the sample data. Basically that is a data came from the website that i mentioned (I am trying to recreate the result before applying it into real data).

Jan	56
Feb	58
Mar	69
Apr	50
May	66
Jun	68
Jul	78
Aug	73
Sept	88
Oct	90

Here is the result that I wish to get in Power BI

However, if Power BI has no memory or concept of self-referencing, then it is impossible doing autocorrelation in Power BI?

Thank you and really appreciate for the help.

Re: Need Help on Autocorrelation Calculation

lbendlin — Sun, 17 Dec 2023 01:48:17 GMT

Ah, that's actually simple - basically a special case for a Pearson correlation within the column. Let me play with that a bit.

Re: Need Help on Autocorrelation Calculation

lbendlin — Sun, 17 Dec 2023 03:48:27 GMT

Here you go

Re: Need Help on Autocorrelation Calculation

Irwan — Sun, 17 Dec 2023 04:35:11 GMT

Hello lbendlin

that DAX is superb, thank you.

I dont know if there is a sumx offset at line 6 (maybe) as a "bridge" before sumx the whole result as in Line 8 (thought it can be done directly by using earlier indexing).

I need to work again on my DAX understanding as a beginner.

Again, thank you and really appreciate for the help.

Re: Need Help on Autocorrelation Calculation

lbendlin — Sun, 17 Dec 2023 13:20:47 GMT

As always you can approach the issue with different DAX functions but you will want to unlearn EARLIER and embrace the window functions. Makes the shifted reference so much easier.

Re: Need Help on Autocorrelation Calculation

Irwan — Wed, 20 Dec 2023 23:23:33 GMT

hello lbendlin

sorry in advance, i got another question, is it possible to put the measure (the correlation result) into a new column?

Thank you and appreciate for the help.

Re: Need Help on Autocorrelation Calculation

lbendlin — Thu, 21 Dec 2023 00:20:13 GMT

You cannot create columns from measures. You would need to modify the code to create a calculated column instead

Re: Need Help on Autocorrelation Calculation

Irwan — Thu, 21 Dec 2023 03:35:12 GMT

Hello lbendlin

alright then, thank you again for the help and support.