将 geom_text 图例中的 'aaa' 更改为相应的标签文本

Question

类似于this question 和this，我的首选输出是将geom_text 的图例作为文本标签，而不是'aaa'。 （即mchild图例圆圈内的'aaa'应该是0,1,2,3,4。请看附图）

这是我的数据：

 data.frame(
            ID = c(1L, 3L, 5L, 11L, 13L, 18L, 20L, 24L, 33L, 34L, 36L),
       sum_hrs = c(12, 8, 68, 44, 16, 12, 36, 16, 4, 20, 4),
  avg_workload = c(263.1615,275.312,269.462444444444,
                   268.867666666667,276.686,257.3605,267.8695,268.3355,
                   239.409,260.230333333333,330.061),
      avg_achv = c(92.5,98,94.2222222222222,
                   94.8333333333333,92,98,94.25,93.5,98,95.3333333333333,100),
        mchild = c(1L, 0L, 1L, 2L, 3L, 0L, 4L, 0L, 2L, 0L, 1L),
       drinker = as.factor(c("No","Yes","Yes",
                             "Yes","Yes","No","Yes","Yes","No","No",
                             "Yes"))
)

我已经尝试过相关 SO 问题中的答案建议，但无法正常工作。很可能我的 grobs 索引不正确。所以我已经阅读了文档，但仍然无法完全理解。这是我到目前为止所做的：

p2 <- ggplot(data=sum_ua, aes(x=avg_achv, y=sum_hrs, size=mchild, color=drinker, alpha=sum_hrs)) +
    geom_point() +
    geom_text(data=sum_ua, aes(x=avg_achv, y=sum_hrs, label=mchild), color='#A9A9A9') +
    scale_size(range=c(4,20)) +
    scale_alpha_binned(range = c(0.01, 1), guide = 'none') +    
    new_scale_color()

g <- ggplotGrob(p2)
lbls <- unique(sort(sum_ua$mchild))
g$grobs[[15]][[1]][[1]]$grobs[[1]]$label <- lbls[1]
g$grobs[[15]][[1]][[1]]$grobs[[6]]$label <- lbls[2]
g$grobs[[15]][[1]][[1]]$grobs[[8]]$label <- lbls[3]

g$grobs[[grep("guide", g$layout$name)]]

grid.draw(g)

这是我的输出：

很抱歉这个基本问题，感谢您的帮助！ :)

Answer 1

作为在情节的 gtable 中乱来的替代方法，您可以为标签美感制作自定义 scale_discrete_identity()。您只需要确保它有一个图例，并且所有信息都与尺寸图例相似（标题、中断、标签等）。

library(ggplot2)
library(ggnewscale)

sum_ua <- data.frame(
  ID = c(1L, 3L, 5L, 11L, 13L, 18L, 20L, 24L, 33L, 34L, 36L),
  sum_hrs = c(12, 8, 68, 44, 16, 12, 36, 16, 4, 20, 4),
  avg_workload = c(263.1615,275.312,269.462444444444,
                   268.867666666667,276.686,257.3605,267.8695,268.3355,
                   239.409,260.230333333333,330.061),
  avg_achv = c(92.5,98,94.2222222222222,
               94.8333333333333,92,98,94.25,93.5,98,95.3333333333333,100),
  mchild = c(1L, 0L, 1L, 2L, 3L, 0L, 4L, 0L, 2L, 0L, 1L),
  drinker = as.factor(c("No","Yes","Yes",
                        "Yes","Yes","No","Yes","Yes","No","No",
                        "Yes"))
)

ggplot(data=sum_ua, aes(x=avg_achv, y=sum_hrs, size=mchild, color=drinker, alpha=sum_hrs)) +
  geom_point() +
  geom_text(data=sum_ua, aes(x=avg_achv, y=sum_hrs, label=as.character(mchild)), color='#A9A9A9') +
  scale_size(range=c(4,20)) +
  scale_alpha_binned(range = c(0.01, 1), guide = 'none') +   
  scale_discrete_identity(guide = "legend", aesthetics = "label",
                          name = "mchild") +
  new_scale_color()

^{由reprex package (v0.3.0) 于 2021-02-01 创建}

Answer 2

对于您的情况，这似乎有效

g <- ggplotGrob(p2)
g$grobs[[15]][[1]][[1]]$grobs[[5]]$label <- 0
g$grobs[[15]][[1]][[1]]$grobs[[8]]$label <- 1
g$grobs[[15]][[1]][[1]]$grobs[[11]]$label <- 2
g$grobs[[15]][[1]][[1]]$grobs[[14]]$label <- 3
g$grobs[[15]][[1]][[1]]$grobs[[17]]$label <- 4
grid::grid.draw(g)

或者为了避免硬编码和重复相同的代码，我们可以使用：

labels <- 0:4
inds <- which(colSums(sapply(g$grobs[[15]][[1]][[1]]$grobs,class) == 'text') > 0)
g$grobs[[15]][[1]][[1]]$grobs[inds] <- Map(function(x, y) {x$label <- y;x}, 
                        g$grobs[[15]][[1]][[1]]$grobs[inds], labels)
grid::grid.draw(g)