R function to transform continuous variable to categorical factor cut at n-tiles

The cut() function can be used to transform a continuous variable into a categorical factor variable. The syntax is quite lengthy and if one wishes to cut at quartiles, quintiles or other n-tiles one has to include the quantile() function into the call.

This is not very newbee friendly and if included into a model-call nearly unreadable.

The function in the code box cutN() does the job.

 cutN <- function(X , n = 4){
     cut(
         X ,
         include.lowest = TRUE ,
         breaks = quantile(
                           X , 
                           probs = (0:n)/n ,
                           na.rm = TRUE ))}

In order to cut the continuous variable Creatinine in the dataset Patients into deciles (n=10) the syntax is:
cutN( Patients$Creatinine , n = 10 )

No big deal, but maybe useful…

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BASH: Convert Uppercase to Lowercase letters

Vivek Gite on nixCraft suggests tr to tranform uppercase letters in the textfile input.txt to lowercase and output the transformed text to output.txt.

tr '[:upper:]' '[:lower:]' output.txt

I needed to clean up a messy old scriptfile where I lost track of my variable naming convention.

Very useful indeed 🙂