sorting - How to sort a character vector where elements contain letters and numbers in R?

Question

I have a character array

cf <- c("V440","V457","V116","V327","V446","V108",
         "V155","V217","V120","V51","V477")

I would like to sort it in descending order so that I will have an output like this:

V51
V108
V116
V120
V155
V217
V327
V440
V446
V457
V477

I have tried sort.list() like this

cf[sort.list(cf)]

and got this answer:

[1] "V108" "V116" "V120" "V155" "V217" "V327" "V440" "V446" "V457" "V477" "V51" 

and also tried order() and got same result.

Can someone help me please

Answer 1

Try mixedsort from the "gtools" package:

> # install.packages("gtools") ## Uncomment if not already installed
> library(gtools)
> mixedsort(cf)
 [1] "V51"  "V108" "V116" "V120" "V155" "V217" "V327" "V440" "V446" "V457" "V477"

---

If you don't want to use mixedsort (not sure why one wouldn't), and if your vector has a pretty consistent pattern (eg letters followed by numbers), you can also probably try something like this. (Note: Relatively untested.)

newvec <- c("V440", "V457", "V116", "V327", "V446", "V108", "V155", 
            "V217", "V120", "V51", "V477", "B22", "A10", "Z01")

newvec[order(gsub("([A-Z]+)([0-9]+)", "\1", newvec), 
             as.numeric(gsub("([A-Z]+)([0-9]+)", "\2", newvec)))]
#  [1] "A10"  "B22"  "V51"  "V108" "V116" "V120" "V155" "V217" "V327" "V440"
# [11] "V446" "V457" "V477" "Z01"