Fifty-five States abbreviations to full names in R

Question

I have a file with a variable state that has 55 states abbreviations. I will like to replace them with the full state name. Is there an easy way to do this in R?

Answer 1

You can use a named list and take advantage of the datasets package :

states <- setNames(as.list(datasets::state.name), datasets::state.abb)

states[["NY"]]

[1] "New York"

Answer 2

If you are doing this for mapping purposes, this longer answer that draws from Waldi's answer above may also be helpful. Given that you have a data frame with state abbreviations and some number to plot, like:

df <- structure(list(abbrev = c("AK", "AL", "AR", "AZ", "CA", "CO", 
"CT", "DC", "DE", "FL", "GA", "GU", "HI", "IA", "ID", "IL", "IN", 
"KS", "KY", "LA", "MA", "MD", "ME", "MI", "MN", "MO", "MS", "MT", 
"NC", "ND", "NE", "NH", "NJ", "NM", "NV", "NY", "OH", "OK", "OR", 
"PA", "PR", "RI", "SC", "SD", "TN", "TX", "UT", "VA", "VI", "VT", 
"WA", "WI", "WV", "WY"), n = c(4L, 20L, 11L, 51L, 98L, 11L, 68L, 
37L, 102L, 116L, 32L, 9L, 29L, 72L, 9L, 191L, 60L, 23L, 12L, 
32L, 43L, 24L, 8L, 65L, 38L, 44L, 15L, 12L, 59L, 11L, 38L, 48L, 
64L, 14L, 21L, 159L, 144L, 34L, 17L, 157L, 18L, 20L, 48L, 13L, 
26L, 175L, 10L, 19L, 4L, 96L, 7L, 104L, 15L, 2L)), row.names = c(NA, 
-54L), class = c("tbl_df", "tbl", "data.frame")) 

You can pull from built-in data to get state name, abbreviation, and even lat/long:

state.info <- inner_join(data.frame(state=state.name, 
     long=state.center$x, lat=state.center$y, stringsAsFactors=FALSE),
     data.frame(state=state.name, abbrev=state.abb))

Then you can bring the datasets together so you have the state abbreviations supplemented by full name as well as lat long:

> inner_join(df, state.info, by="abbrev")
# A tibble: 50 x 5
   abbrev     n state         long   lat
   <chr>  <int> <chr>        <dbl> <dbl>
1 AK         4 Alaska      -127.   49.2
2 AL        20 Alabama      -86.8  32.6
3 AR        11 Arkansas     -92.3  34.7
4 AZ        51 Arizona     -112.   34.2
5 CA        98 California  -120.   36.5
6 CO        11 Colorado    -106.   38.7
7 CT        68 Connecticut  -72.4  41.6
8 DE       102 Delaware     -75.0  38.7
9 FL       116 Florida      -81.7  27.9