我怎样才能让这个 ggplot 渲染得更快？

如何解决我怎样才能让这个 ggplot 渲染得更快？

以下是我正在处理的数据的再现。 geom_segment 调用使渲染非常缓慢。有没有其他方法可以更快地获得相同的结果？

library(ggplot2)
library(ggridges)

n <- 5000; l <- c(2,5,7,9); sd_27 <- c(5.9,11,14,17)
df <- data.frame(name = c(rep("A",n),rep("B",rep("C",rep("D",n)),value = c(rpois(n,l[1]),rpois(n,l[2]),l[3]),l[4])))

ggplot(df,aes(x = value,y = name,fill = name)) + geom_density_ridges(alpha = 0.8) +
  geom_segment(aes(x = l[[1]],y = "A",xend = l[[1]],yend = 2,color = "mean")) +
  geom_segment(aes(x = l[[2]],y = "B",xend = l[[2]],yend = 3,color = "mean")) +
  geom_segment(aes(x = l[[3]],y = "C",xend = l[[3]],yend = 4,color = "mean")) +
  geom_segment(aes(x = l[[4]],y = "D",xend = l[[4]],yend = 5,color = "mean")) +
  geom_segment(aes(x = sd_27[[1]],xend = sd_27[[1]],color = "sd_27")) +
  geom_segment(aes(x = sd_27[[2]],xend = sd_27[[2]],color = "sd_27")) +
  geom_segment(aes(x = sd_27[[3]],xend = sd_27[[3]],color = "sd_27")) +
  geom_segment(aes(x = sd_27[[4]],xend = sd_27[[4]],color = "sd_27"))

解决方法

不是通过单独的 geom_segment 层添加每个段，您可以将段的所有数据放在一个数据框中，并通过一个 geom_segment 添加段，根据 microbenchmark 减少渲染时间约为五分之一：

geom_segment

library(ggplot2)
library(ggridges)

set.seed(42)

n <- 5000; l <- c(2,5,7,9); sd_27 <- c(5.9,11,14,17)
df <- data.frame(name = c(rep("A",n),rep("B",rep("C",rep("D",n)),value = c(rpois(n,l[1]),rpois(n,l[2]),l[3]),l[4])))

dl <- data.frame(x = l,y = LETTERS[1:4],yend = 2:5,color = "mean")
dsd <- data.frame(x = sd_27,color = "sd_27")

d <- do.call(rbind,list(dl,dsd))

p1 <- function() {
  ggplot(df,aes(x = value,y = name,fill = name)) + 
    geom_density_ridges(alpha = 0.8) +
    geom_segment(data = d,aes(x = x,y = y,xend = x,yend = yend,color = color),inherit.aes = FALSE)
}

p2 <- function() {
  ggplot(df,fill = name)) + geom_density_ridges(alpha = 0.8) +
    geom_segment(aes(x = l[[1]],y = "A",xend = l[[1]],yend = 2,color = "mean")) +
    geom_segment(aes(x = l[[2]],y = "B",xend = l[[2]],yend = 3,color = "mean")) +
    geom_segment(aes(x = l[[3]],y = "C",xend = l[[3]],yend = 4,color = "mean")) +
    geom_segment(aes(x = l[[4]],y = "D",xend = l[[4]],yend = 5,color = "mean")) +
    geom_segment(aes(x = sd_27[[1]],xend = sd_27[[1]],color = "sd_27")) +
    geom_segment(aes(x = sd_27[[2]],xend = sd_27[[2]],color = "sd_27")) +
    geom_segment(aes(x = sd_27[[3]],xend = sd_27[[3]],color = "sd_27")) +
    geom_segment(aes(x = sd_27[[4]],xend = sd_27[[4]],color = "sd_27"))
}

# Check plot
p1()
#> Picking joint bandwidth of 0.381

# Compare running time
microbenchmark::microbenchmark(p1()) 
#> Unit: milliseconds
#>  expr      min       lq     mean   median      uq      max neval
#>  p1() 1.859514 1.917135 2.162416 1.936781 2.42122 5.056147   100
microbenchmark::microbenchmark(p2())
#> Unit: milliseconds
#>  expr     min       lq     mean   median       uq      max neval
#>  p2() 9.37298 9.669749 10.20821 9.774624 10.17852 22.42459   100