Limiting the number of decimals in a dataframe (R)

Question

I would like to limit the number of decimals when a data frame is imported. My .txt input have 16 decimals to each row in collumn "Value". My dataframe look like that:

Value   0.202021561664556 0.202021561664556 0.202021561664556 0.202021561664556 ... 

My expected dataframe

Value 0.20202156 0.20202156 0.20202156 0.20202156 ... 

Real input (DF) that not works:

DF <- "NE001358.Log.R.Ratio     -0.0970369274475688     0.131893549586039     0.0629266495860389     0.299559132381831     -0.0128804337656807     0.0639743960526874     0.0271669351886552     0.322395363972391     0.179591292893632"  DF <- read.table(text=DF, header = TRUE) 

Answer 1

Here is.num is TRUE for numeric columns and FALSE otherwise. We then apply round to the numeric columns:

is.num <- sapply(DF, is.numeric) DF[is.num] <- lapply(DF[is.num], round, 8) 

If what you meant was not that you need to change the data frame but just that you want to display the data frame to 8 digits then it's just:

print(DF, digits = 8) 

In dplyr 1.0.0 and later one can use across within mutate like this:

library(dplyr) DF %>% mutate(across(where(is.numeric), ~ round(., 8)))