Is there a function in R that allows to select rows where the row name ends in a lower case letter, and remove this letter?

Question

I have the following data.frame:

data <- as.data.frame(seq(1:5))
rownames(data) <- c("abc-2A","abc-2b", "def-3", "ACD4.54Y", "ghj-5c")
data
             seq(1:5)
abc-2A          1
abc-2b          2
def-3           3
ACD4.54Y        4
ghj-5c          5

I would like to do two things with this data frame:

1. Make a subset of this data frame that contains only the rows where there row name ends with a lower case letter. This would be:

            seq(1:5)
   abc-2b          2
   ghj-5c          5
   

2. Remove this lower case letter from the row names in the original data.frame. The final data.frame would be:

        seq(1:5)
   abc-2A          1
   abc-2           2
   def-3           3
   ACD4.54Y        4
   ghj-5           5
   

I have spent quite some time in stack overflow and google but I couldn't figure out how to do it. Does anyone have a suggestion?

Thanks a lot!

Answer 1

you can use the dplyr::filterfunction to filter rows according to some criteria. Lower case letters at the end of a string can be identified with regular expressions like this [a-z]$. Combining all of this yields the following

library(dplyr)
  mydata <- data.frame(id = c("select thiss", "DONT SELECT"), x = 1:2) 

mydata %>% 
    filter(grepl("[a-z]$", id)) %>% 
    mutate(id = sub("[a-z]$", "", id))

           id x
1 select this 1