创建超过 2 组的高图表密度

我尝试用两个以上的组创建高图表密度。我找到了一种手动将它们逐一添加的方法，但必须有更好的方法来处理组。

示例：我想创建一个类似于下面的ggplot图表的highchart，而不需要将它们一一添加。有什么办法可以做到吗？

d

f <- data.frame(MEI = c(-2.031, -1.999, -1.945, -1.944, -1.875, 
                       -1.873, -1.846, -2.031, -1.999, -1.945, -1.944, -1.875, -1.873, 
                       -1.846, -2.031, -1.999, -1.945, -1.944, -1.875, -1.873, -1.846, 
                       -2.031, -1.999, -1.945, -1.944, -1.875, -1.873, -1.846), 
                 Count = c(10L,0L, 15L, 1L, 6L, 10L, 18L, 10L, 0L, 15L, 1L, 6L, 10L, 0L, 15L, 
                          10L, 0L, 15L, 1L, 6L, 10L, 10L, 0L, 15L, 1L, 6L, 10L, 18L), 
                 Region = c("MidWest", "MidWest", "MidWest", "MidWest", "MidWest", "MidWest", "MidWest", 
                                        "South", "South", "South", "South", "South", "South", "South", 
                                        "South", "South", "South", "NorthEast", "NorthEast", "NorthEast", 
                                        "NorthEast", "NorthEast", "NorthEast", "NorthEast", "NorthEast", 
                                        "NorthEast", "NorthEast", "NorthEast"))
df <- data.table(ddf)
df %>%ggplot() + 
  geom_density(aes(x=MEI, group=Region, fill=Region),alpha=0.5) + 
  xlab("MEI") +
  ylab("Density")

hcdensity(df[Region=="NorthEast"]$MEI,area = TRUE) %>%
  hc_add_series(density(df[Region=="MidWest"]$MEI), area = TRUE) %>%
  hc_add_series(density(df[Region=="South"]$MEI), area = TRUE)

方法一： tapply + reduce + hc_add_series

tapply(df$MEI, df$Region, density) %>%
  reduce(.f = hc_add_series, .init = highchart())

方法二： map + hc_add_series_list

（参考：RPubs - Highcharter hc_add_series_list https://rpubs.com/jbkunst/hc_add_series_list)

ds <- map(levels(df$Region), function(x){
  dt <- density(df$MEI[df$Region == x])[1:2]
  dt <- list_parse2(as.data.frame(dt))
  list(data = dt, name = x)
})

highchart() %>% 
  hc_add_series_list(ds)