Table gets empty when looping through a column

[didierjoc]

Hi everyone,

I have a question concerning the use of R to transform data in Power BI.

I am working on this table and trying to replace the first column data.

I have trouble understanding how does R code can really interact with data, and I am a beginner in R. This might be why I get this error :

I wrote this script (trying, as a test, to replace all values of the first column by 1) and when I run it, the data seems to be empty :

ctr <- 0

for (day in dataset[,1]) {
ctr <- ctr + 1
dataset[,1][ctr] <- 1
}

I thought someone may have a solution.

Thanks,

Baptiste

[v-huizhn-msft · Accepted solution]

Hi @didierjoc,

In your R scrip, there are no result, so it returns empty table. I try to reproduce you scenario and get expected result.
The following is sample data, I replace the first column data to 1.


 
In the Power Query Editor, click the “Run R Scripts”, type the following script and click OK.

ctr <- 0for (day in dataset[,1]) {ctr <- ctr + 1 dataset[,1][ctr] <- 1}output<-dataset

 
Finally, click Apply&Close, you will get the expected result as the following screenshot.


 

If you have any other issue, please feel free to ask.

Best Regards,
Angelia

[didierjoc]

Hi Angelia,

It works indeed, I didn't know I had to do so !

Thanks a lot !

Didier