Using R script in Power Query - Error associated with factor level recognition

[edaugherty]

I have an Excel file that I want to transform in Power Query using R script. The script runs fine in R Studio, but when I run it as a query in Power Query, I get the error: Error in relevel.factor(dataset_name$Column6, ref = "FactorA") : 'ref' must be an existing level.

ErrorCode=-2147467259
ExceptionType=Microsoft.PowerBI.Scripting.R.Exceptions.RScriptRuntimeException

'Ref' is an existing level, and as I mentioned, this section of code runs correctly in R Studio. Prior to this step, Power BI applies the following steps automatically when I bring in the Excel file and select Transform Data:

Is one of these steps changing something in the data that is making it difficult for R to recognize the data type? I have used this same code in Power BI through the Get Data > R script functionality (along with file path information in the R code) without a problem.

I am wanting to use R in Power Query to hopefully be able to change the data source to other files with the same structure, and then Power BI will automatically run it through the queries and update the visuals according to the new data file.

Thank you!

Ellen

[amitchandak]

@edaugherty , Have you installed all required packages, refer : https://docs.microsoft.com/en-us/power-bi/connect-data/desktop-r-in-query-editor

or

https://www.red-gate.com/simple-talk/sql/bi/power-bi-introduction-working-with-r-scripts-in-power-bi...

https://www.thebiccountant.com/2017/08/25/tips-and-tricks-for-r-scripts-in-the-query-editor-in-power...

[edaugherty]

Thanks for responding, @amitchandak!

I assume you mean the R packages. Yes, all necessary packages are installed and loaded. In any case, the function causing problems is from base R, not a package. As I mentioned, the script works just fine when used through the Get Data > R script pathway. It does not work when I use it to transform the original Excel file in Power BI's Power Query.

[edaugherty · Accepted solution]

It would appear that the problem was due to a space being entered at the end of "Factor A ". Trimming white space solved the problem. Of course, now I have another problem, but I'll put that in another thread.