Question

我有一个有两行的情节，其中图例条目非常相似，除了一些单词（见下文）。

我的代码如下所示：

library(tidyverse)

set.seed(36)
Data <- data.frame(
  date = sample((as.Date(as.Date("2011-12-30"):as.Date("2012-01-04"),
                         origin="1970-01-01")), 1000, replace = TRUE),
  group = sample(c("0", "1"), 1000, replace = TRUE),
  outcome = sample(c("0", "1"), 1000, replace = TRUE))
Data %>%
  mutate(date = as.POSIXct(date), group = factor(group)) %>%
  group_by(group, date) %>% #group
  summarise(prop = sum(outcome == "1")/n()) %>% #calculate proportion 
  ggplot()+
  geom_line(aes(x = date, y = prop, color = group))+
  geom_point(aes(x = date, y = prop, color = group)) +
  scale_color_manual(values = c("0" = "blue", "1" = "black"), labels = c("0" = 'Some text that repeats, the only unique thing being "A"', "1" = 'Some text that repeats, the only unique thing being "B"'), name = "Legend")

它生成以下图表：

我想简化传说。它应包含以下几行：

标题（Legend），
没有任何彩色线条的文字（Some text that repeats, the only unique thing being），然后是带
包含文字A和
带有文字B的黑线。

即。所需的输出看起来像这样：

我怎样才能做到这一点？

Answer 1

以下是提案：

scale_color_manual(values = c("0" = "blue", "1" = "black"), 
                   labels = c("0" = '"A"', "1" = '"B"'), 
                   name = "Legend\nSome text that repeats,\nthe only unique thing being")

但我会删除"Legend"（不是非常有用的恕我直言）。

要明确区分"Legend"和字幕文字，您可以使用expression和atop加粗：

legend_title = expression(atop(bold("Legend\n"),
                         "Some text that repeats,\nthe only unique thing being"))

Data %>%
  mutate(date = as.POSIXct(date), group = factor(group)) %>%
  group_by(group, date) %>% #group
  summarise(prop = sum(outcome == "1")/n()) %>% #calculate proportion 
  ggplot()+
  geom_line(aes(x = date, y = prop, color = group))+
  geom_point(aes(x = date, y = prop, color = group)) +
  scale_color_manual(values = c("0" = "blue", "1" = "black"), 
                     labels = c("0" = '"A"', "1" = '"B"'), 
                     name = legend_title)

然后您可以在"Legend"之后添加空格以将其对齐到左侧：

legend_title = expression(atop(bold("Legend                             \n"),
                         "Some text that repeats,\nthe only unique thing being"))

Answer 2

这是一种方法，只是略显苛刻：使用group中的fct_expand（包含在tidyverse中）为您的forcats变量添加虚拟级别，然后使用fct_relevel来使它成为因素的第一级。这样，您就会在图例顶部列出一个虚假的观察结果，但实际上并没有附带任何数据。

除了添加该行之外，我唯一改变的是drop = F色标，因此即使没有与虚拟关卡相关的数据，它仍会显示在图例中，然后显示图例标签。 / p>

一个缺点是虚拟变量的图例键是可见的;可能有一些方法可以摆脱它，或者你可以通过给图例键设置白色背景来降低它的可见度。

library(tidyverse)

set.seed(36)
Data <- data.frame(
    date = sample((as.Date(as.Date("2011-12-30"):as.Date("2012-01-04"),
                                                 origin="1970-01-01")), 1000, replace = TRUE),
    group = sample(c("0", "1"), 1000, replace = TRUE),
    outcome = sample(c("0", "1"), 1000, replace = TRUE))
Data %>%
    mutate(date = as.POSIXct(date), group = factor(group)) %>%
# add a dummy factor level & make it the first level
    mutate(group = group %>% fct_expand("dummy") %>% fct_relevel("dummy")) %>%
    group_by(group, date) %>% #group
    summarise(prop = sum(outcome == "1")/n()) %>% #calculate proportion 
    ggplot()+
    geom_line(aes(x = date, y = prop, color = group))+
    geom_point(aes(x = date, y = prop, color = group)) +
    scale_color_manual(values = c("0" = "blue", "1" = "black", "dummy" = "transparent"), labels = c("0" = "A", "1" = "B", "dummy" = "Some text that repeats,\nthe only unique thing being"), name = "Legend", drop = F)

由reprex package（v0.2.0）创建于2018-04-09。

添加文本到图例，而不参考图中的线

2 个答案: