check if all characters of one string exist in another string in r

Question

I am trying to compare strings like PRABHAKAR SHARMA and SHARMA KUMAR PRABHAKAR. the intention is to check if all the characters of the shorter str

Answer 1

If the characters to be considered are only letters you could use:

comp <- function(s1, s2){         
     in1 = letters %in% strsplit(tolower(s1), "")[[1]]
     in2 = letters %in% strsplit(tolower(s2), "")[[1]]
     sum(in1 & in2)/sum(in1)
}

Answer 2

Here is one approach

s1 <- "PRABHAKAR SHARMA"
s2 <- "SHARMA KUMAR PRABHAKAR"

compare <- function(s1, s2) {
    c1 <- unique(strsplit(s1, "")[[1]])
    c2 <- unique(strsplit(s2, "")[[1]])
    length(intersect(c1,c2))/length(c1)
}

compare(s1,s2)
#1

It may be a little slow, though. And it considers the space character as character, too. Use Vectorize to apply on a column:

dat <- data.frame(small=c("a", "b"), big=c("aa", "cc"), stringsAsFactors=FALSE)
vcomp <- Vectorize(compare)
dat <- transform(dat, comp=vcomp(small, big))