パッケージ「choroplethr」と単純なdf2データセット（同じ地域と値の列があります）を使用して米国の州マップを作成しようとしましたが、パッケージドキュメントで提供されているコードを使用しました。
require (choroplethr)
data("df_pop_state")
df2 <- read.csv("ShareDF-chro.csv", header=TRUE, stringsAsFactors=FALSE)
# here is the data ShareDF-chro
region = c("alabama", "alaska", "arizona", "arkansas",
"california", "colorado", "connecticut", "delaware", "district of columbia",
"florida", "georgia", "hawaii", "idaho", "illinois", "indiana",
"iowa", "kansas", "kentucky", "louisiana", "maine", "maryland",
"massachusetts", "michigan", "minnesota", "mississippi", "missouri",
"montana", "nebraska", "nevada", "new hampshire", "new jersey",
"new mexico", "new york", "north carolina", "north dakota", "ohio",
"oklahoma", "oregon", "pennsylvania", "rhode island", "south carolina",
"south dakota", "tennessee", "texas", "utah", "vermont", "virginia",
"washington", "west virginia", "wisconsin", "wyoming"),
value = c(1.15, 0.11, 6.21, 2.41, 8.42, 13.57, 3.57, 4.55, 7.08, 9.42, 5.21,
0.108, 9.09, 2.56, 4.51, 9.65, 6.76, 3.54, 0.17, 1.99, 6.66,
3.88, 7.31, 4.86, 4.85, 2.39, 0.25, 0.05, 0.21, 0.11, 3.86, 0.05,
7.31, 1.91, 0.41, 4.55, 0.002, 2.65, 3.14, 0.71, 1.94, 0.13,
2.2, 12.65, 0.05, 0.074, 5.79, 7.5, 0.12, 2.6, 0.33)
df_pop_state$value <- df2$value
state_choropleth(df_pop_state,title = "US State's X-Capital share data",num_colors = 2,legend = "Capital Share")
私の質問は次のとおりです。対応する X-capital シェア値を州の頭字語とともにマップ内に挿入するにはどうすればよいですか (頭字語のフォント サイズを少し小さくしたい場合)。ありがとうございます。