Convert state abbreviation into full name (or opposite)

abb2state.R

abb2state <- function(name, convert = F, strict = F){
  data(state)
  # state data doesn't include DC
  state = list()
  state[['name']] = c(state.name,"District Of Columbia")
  state[['abb']] = c(state.abb,"DC")
  
  if(convert) state[c(1,2)] = state[c(2,1)]
  
  single.a2s <- function(s){
    if(strict){
      is.in = tolower(state[['abb']]) %in% tolower(s)
      ifelse(any(is.in), state[['name']][is.in], NA)
    }else{
      # To check if input is in state full name or abb
      is.in = rapply(state, function(x) tolower(x) %in% tolower(s), how="list")
      state[['name']][is.in[[ifelse(any(is.in[['name']]), 'name', 'abb')]]]
    }
  }
  sapply(name, single.a2s)
}


# Examples:
# > abb2state(c("UT", "NC"))
#               UT               NC 
#           "Utah" "North Carolina"
#
# > abb2state(c("South Carolina", "Utah", "North Carolina"), convert=T)
# South Carolina           Utah North Carolina 
#           "SC"           "UT"           "NC"
#
# > abb2state(c("South Carolina", "Utah", "NC", "Arizona"))
#   South Carolina             Utah               NC          Arizona 
# "South Carolina"           "Utah" "North Carolina"        "Arizona" 
# 
# > abb2state(c("South Carolina", "Utah", "NC", "Arizona"), strict = T)
#   South Carolina             Utah               NC          Arizona 
#               NA               NA "North Carolina"               NA