How to replace many strings written in different ways to a unified way of writing the term?

Question

I have this df

df = data.frame(x = c('Orange','orange','Appples','orgne','apple','applees','oranges','Oranges',
                      'orgens','orgaanes','Apples','ORANGES','apple','APPLE') )

using str_replace_all, I know I can replace each one of these terms to a one unified way of writing each of the 2 words orange and apple but it would take forever if you have a lot of terms in the dataframe. Would wanna a simple way of coding in order to unify all the ways of writing into orange and apple.

Answer 1

You can use agrep for approximate string matching:

for (i in c("orange", "apple")){
  df$x[agrep(i, df$x, max.distance = 2, ignore.case = TRUE)] <- i
  df$x
}

#[1] "orange"   "orange"   "apple"    "orange"   "apple"   "apple"    "orange"   "orange"   "orange"   "orgaanes" "apple"    "orange"   "apple"    "apple"  

You can change the sensitivity of the distances with max.distance.

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Another possibility is the stringdist package, which has a number of different distance metrics:

library(stringdist)
v <- c("orange", "apple")
v[amatch(tolower(df$x), v, maxDist = 3)]