require(rCharts)
make_dataset = function(data = data){
  lapply(toJSONArray2(data, json = F, names = F), unlist)
}
dart <- data.frame(
  score = c(20,1,18,4,13,6,10,15,2,17,3,19,7,16,8,11,14,9,12,5),
  measure = rep(451/2, 20)  #451 mm diameter
)
dartboard <- rCharts$new()
dartboard$setLib(
  "//rcharts.io/howitworks/libraries/widgets/micropolar"
)
dartboard$set(
  data = make_dataset( dart ),
  radialDomain = c(0, 225),
  radialTicksSuffix = '',
  angularDomain = as.character(dart$score),
  minorTicks = 0,
  type = "areaChart",
  height = 300,
  width = 300
)
dartboard