Replace specific characters within strings

I would like to remove specific characters from strings within a vector, similar to the Find and Replace feature in Excel.

Here are the data I start with:

group <- data.frame(c("12357e", "12575e", "197e18", "e18947")

I start with just the first column; I want to produce the second column by removing the e's:

group       group.no.e
12357e      12357
12575e      12575
197e18      19718
e18947      18947

Solution 1:

With a regular expression and the function gsub():

group <- c("12357e", "12575e", "197e18", "e18947")
group
[1] "12357e" "12575e" "197e18" "e18947"

gsub("e", "", group)
[1] "12357" "12575" "19718" "18947"

What gsub does here is to replace each occurrence of "e" with an empty string "".

See ?regexp or gsub for more help.

Solution 2:

Regular expressions are your friends:

R> ## also adds missing ')' and sets column name
R> group<-data.frame(group=c("12357e", "12575e", "197e18", "e18947"))  )
R> group
   group
1 12357e
2 12575e
3 197e18
4 e18947

Now use gsub() with the simplest possible replacement pattern: empty string:

R> group$groupNoE <- gsub("e", "", group$group)
R> group
   group groupNoE
1 12357e    12357
2 12575e    12575
3 197e18    19718
4 e18947    18947
R>