Adding a column with exact matches from a list-CodePudding

I have data as follows:

library(data.table)
dat <- fread("varA, varB
              some_string a1
              other_string a3
              blabla a3_2")

renaming_list <- c(
  some_name = "a1",
  other_name = "a3")

I am probably overthinking this, but I would like to match var_B with the naming list to make:

dat <- fread("varA, varB name
              some_string a1 some_name
              other_string a3 other_name
              blabla  NA")

How should I match these? I was previously using a code that uses non-exact matches,

dat[, panel_name:=apply(outer(renaming_list, varB, Vectorize(grepl)), 2, \(x) 
                  if (any(x)) names(which(x)) else NA)]

but now I only want exact matches. How should I adapt this code?

CodePudding user response：

rl2 = setNames(names(renaming_list), renaming_list)
dat[, varB := rl2[varB]]

dat
#          varA,       varB
#          <char>     <char>
# 1:  some_string  some_name
# 2: other_string other_name
# 3:       blabla       <NA>

CodePudding user response：

With match:

dat[, name := names(renaming_list)[match(varB, renaming_list)]]

          varA, varB       name
1:  some_string   a1  some_name
2: other_string   a3 other_name
3:       blabla a3_2       <NA>