CODEWITHSUNDEEP
rgis
wwl
wwl

Reputation: 2065

automatically titling figures and maps in R

I'm using R to generate a map of percentage of voters that voted Democrat and Republican for each election since 1948. So I have a map of the US (broken down into states), and I want to generate two maps for each election (one for each party).

I'm using the GIStools and rgdal library, and my tentative code is like this:

variablelist = c("Dem1948", "Rep1948", ..., "Dem2012", "Rep2012")

for (variable in variablelist) {
  shades <- auto.shading(USA$variable, n = 5, cols = brewer.pal(5, "Blues"))
  choropleth(USA, USA,variable, shades)
  choro.legend(-91, 27, shades, fmt = "%g", title = "Voting Percentage")
}

The problem is my title (see the last line) is very generic for every map. How can I automatically make the title for "Dem1948" to be "Percentage that voted for Democrats in 1948", and so on?

Upvotes: 0

Views: 40

Answers (1)

tobiasegli_te
tobiasegli_te

Reputation: 1463

You could add the following to your code:

party_use <- ifelse(grepl("Dem",variable),"Democrats","Republicans")
year_use <- substr(variable,4,7)

choro.legend(-91, 27, shades, fmt = "%g", title = paste0("Percentage that voted for ", party_use," in ", year_use))

Upvotes: 1

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