问ggplot2在Mac和Windows上的性能差异很大

EN

library(data.table)
library(ggplot2)
library(glue)
theme_set(theme_bw())

dat <- list()
n = 51
i <- 1
for (linetype in 1:2) {
  for (color in 1:5) {
    for (v in 1:16) {
      dat[[i]] <- data.table(
        linetype=glue("L{linetype}"),
        color=glue("C{color}"),
        variable=glue("V{v}"),
        period=1:n,
        value=rnorm(n)
      )
      i <-i + 1
    }
  }
}

dat <- rbindlist(dat)

system.time({
  pdf("test.pdf", onefile=TRUE)
  for (i in 1:10) {
    print(ggplot(dat, aes(period, value, color=color, linetype=linetype))+geom_line()+facet_wrap(~variable))
  }
  dev.off()
})