使用Furrr未来地图保存拼布GGPLOTS仅保存其中一个图

Question

我正在尝试保存拼打ggplots的列表（即使用软件包patchwork 将已包装到1个图中的ggplots）。

我的真实数据是创建数百个图，因此我想使用furrr将其加快。使用furrr :: future_map可以很好地保存标​​准的GGPLOT，但是当我在patchwork绘制绘图上时，它只是保存其中一个图。请参阅下面的一些默认GGPLOT，以代替我实际的长图。

由furrr :: Map保存的图总是是拼布图中的最后一个图（右下）。

有谁知道为什么future_imap和imap在这里表现不同，并且可以做任何事情？

library(ggplot2)
library(patchwork)
library(purrr)
library(furrr)
#> Loading required package: future
plan(multisession, workers =  availableCores() - 1)

#make some example plots
p <- ggplot(mtcars, aes(wt, mpg))
p1 <- p + geom_point()
p2 <- p + geom_point(aes(colour = factor(cyl)))
p3 <- p + geom_point(aes(shape = factor(cyl)))
p4 <- p + geom_point(aes(size = qsec))

#make some example patchwork plots
allplots <- patchwork::wrap_plots(p1,p2,p3,p4)
allplots2 <- patchwork::wrap_plots(p1,p3,p2,p4)
allplots3 <- patchwork::wrap_plots(p3,p1,p2,p4)
allplots4 <- patchwork::wrap_plots(p4,p1,p2,p1)

#save list of standard ggplots to confirm future can output normal plots as expected
# These all look basically the same except small differences in resolution (not setting so not worried about this)
list_of_plots <- list("one"=p1,"two"=p2,"three"=p3,"four"=p4)
plots_save_imap <- imap(list_of_plots, ~ggsave(file.path("C:/temp/test",paste0(.y, ".png")), plot = .x))
#> Saving 7 x 5 in image
#> Saving 7 x 5 in image
#> Saving 7 x 5 in image
#> Saving 7 x 5 in image
plots_save_futureimap <- future_imap(list_of_plots, ~ggsave(file.path("C:/temp/test",paste0(.y, "future.png")), plot = .x))
#> Saving 7 x 7 in image
#> Saving 7 x 7 in image
#> Saving 7 x 7 in image
#> Saving 7 x 7 in image
# all look fine

#save list of patchworks

list_of_allplots <- list("first"= allplots,"second"= allplots2,"third"= allplots3,"fourth"= allplots4)

plots_save_imapPW <- imap(list_of_allplots, ~ggsave(file.path("C:/temp/test",paste0(.y, ".png")), plot = .x))
#> Saving 7 x 5 in image
#> Saving 7 x 5 in image
#> Saving 7 x 5 in image
#> Saving 7 x 5 in image

示例：所有4个子图

plots_save_futureimapPW <- future_imap(list_of_allplots, ~ggsave(file.path("C:/temp/test",paste0(.y, "future1.png")), plot = .x))
#> Saving 7 x 7 in image
#> Saving 7 x 7 in image
#> Saving 7 x 7 in image
#> Saving 7 x 7 in image

一样

如果我刚刚运行

plots_futureimapPW <- future_imap(list_of_allplots, ~print(.x))
plots_futureimapPW

，则plots_futureimappw确实为我提供了在2022-05-13创建的rstudio ^{中的完整patchworks}

，由 reprex软件包（v2.0.1）