Say, you have a data frame with a number of columns, and you need to change every column in a similar way. A common example might be to standardize all (numeric) variables. How to do that in R? This post shows and explains an example using mutate_all() from the tidyverse. Let’s stick to the question “how to z-standardize all columns” for the sake of simplicity (and neglect that there are precooked solutions, for example from the superb package sjmisc by …