使用来自 DF 列表的数据在多个图上使用 geom_segment 添加线

Question

我正在尝试向已保存的 ggplot 对象添加多行。线条的坐标存储在数据框列表中，每个单独的图都有一个数据框。我使用 lapply 成功创建了多个绘图，但是，调用 geom_segment 时代码失败。下面是示例数据和代码。

library(ggplot2)
library(tidyverse)
data(iris)
#Dataframes
m.slen <- iris[,c(1,5)]
m.swid <- iris[,c(2,5)]
m.plen <- iris[,c(3,5)]
m.pwid <- iris[,c(4,5)]
#List of dataframes
m.list = list(m.slen = m.slen,
              m.swid = m.swid,
              m.plen = m.plen,
              m.pwid = m.pwid)
#Setting col names
m.list <- lapply(m.list, setNames, nm = c("data", "species"))
#Creating list of data frames with coordinates for geom_segment
meanV = lapply(m.list, function(x) mean(x$data, na.rm = TRUE))
coordy1 = lapply(m.list, function(x) x %>%
                     group_by(species) %>%
                     summarise(max = max(data, na.rm=TRUE)) %>%
                     pull(max) + 2)
#Table with dynamic values
line.plot <- list()
for(i in 1:4) {
line.plot[[i]] <-
    tibble(x1 = meanV[[i]],
           x2 = meanV[[i]]+1,
           y1 = coordy1[[i]][1],
           y2 = coordy1[[i]][1])
               }
#Creating first set of plots, using first list of DFs
plots <- lapply(m.list,function(x)
    p <- ggplot(x, aes( x= data, fill = species)) +
          geom_histogram(stat = "count") +
          ggtitle(names(m.list)))
print(plots)

#Adding segments using second list of DFs
final_plots <- lapply(plots,function(x)
     plots +  geom_segment(data = line.plot,
                       aes(x = x1, y = y1, xend = x2, yend = y2)))

一切正常，直到最后一步，我收到以下错误

Error in fortify(): ! data must be a data frame, or other object coercible by fortify(), not a list

欢迎任何意见或建议。谢谢

Answer 1

问题是 line.plot 是一个列表。为了达到您想要的结果，您可以使用 purrr::map2 遍历您的地块列表和段的数据帧列表：

注意：我还添加了 inherit.aes = FALSE 到 geom_segment，否则你也会得到一个错误。

final_plots <- purrr::map2(plots, line.plot, function(x, y) {
  x + geom_segment(
    data = y,
    aes(x = x1, y = y1, xend = x2, yend = y2), inherit.aes = FALSE
  )
})

final_plots[[1]]

EDIT 使用 base R 你可以用 mapply:

获得相同的结果

final_plots <- mapply(function(x, y) {
  x + geom_segment(
    data = y,
    aes(x = x1, y = y1, xend = x2, yend = y2), inherit.aes = FALSE
  )
}, x = plots, y = line.plot, SIMPLIFY = FALSE)

或者感谢@Parfait 使用 Map:

的评论

final_plots <- Map(function(x, y) {
  x + geom_segment(
    data = y,
    aes(x = x1, y = y1, xend = x2, yend = y2), inherit.aes = FALSE
  )
}, x = plots, y = line.plot)

使用来自 DF 列表的数据在多个图上使用 geom_segment 添加线

Adding lines using geom_segment on multiple plots with data from a list of DFs

r

list

dataframe

ggplot2

lapply