How to remove all special characters from string in R and replace them with spaces ?
Some special characters to remove are : ~!@#$%^&*(){}_+:"<>?,./;'[]-=
I've tried regex with [:punct:] pattern but it removes only punctuation marks.
Question 2 : And how to remove characters from foreign languages like : â í ü Â á a e s c ?
Answer : Use [^[:alnum:]] to remove~!@#$%^&*(){}_+:"<>?,./;'[]-= and use [^a-zA-Z0-9] to remove also â í ü Â á a e s c in regex or regexpr functions.
Solution in base R :
x <- "a1~!@#$%^&*(){}_+:\"<>?,./;'[]-="
gsub("[[:punct:]]", "", x) # no libraries needed
You need to use regular expressions to identify the unwanted characters. For the most easily readable code, you want the str_replace_all from the stringr package, though gsub from base R works just as well.
The exact regular expression depends upon what you are trying to do. You could just remove those specific characters that you gave in the question, but it's much easier to remove all punctuation characters.
x <- "a1~!@#$%^&*(){}_+:\"<>?,./;'[]-=" #or whatever
str_replace_all(x, "[[:punct:]]", " ")
(The base R equivalent is gsub("[[:punct:]]", " ", x).)
An alternative is to swap out all non-alphanumeric characters.
str_replace_all(x, "[^[:alnum:]]", " ")
Note that the definition of what constitutes a letter or a number or a punctuatution mark varies slightly depending upon your locale, so you may need to experiment a little to get exactly what you want.
Instead of using regex to remove those "crazy" characters, just convert them to ASCII, which will remove accents, but will keep the letters.
astr <- "Ábcdêãçoàúü"
iconv(astr, from = 'UTF-8', to = 'ASCII//TRANSLIT')
which results in
[1] "Abcdeacoauu"
Convert the Special characters to apostrophe,
Data <- gsub("[^0-9A-Za-z///' ]","'" , Data ,ignore.case = TRUE)
Below code it to remove extra ''' apostrophe
Data <- gsub("''","" , Data ,ignore.case = TRUE)
Use gsub(..) function for replacing the special character with apostrophe
Source: Stackoverflow.com