如何控制ggrepel片段的颜色

Question

我将在一个更好的MRE...for环境中再次尝试，下面是我目前正在尝试改进的产品

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我要做的是让从端点到标签的线条与数据线的颜色相同。

对于这个问题，我们可以使用这个脚本

library(ggplot2)
library(babynames)
library(dplyr)
library(ggrepel)
library(ggsci)

data <- babynames %>%
  filter(name %in% c("Ashley", "Patricia", "Mary", "Minnie")) %>%
  filter(sex=="F")

data <- data %>% group_by(name) %>%
  mutate(change = n - lag(n)) %>% 
  mutate(meanC = mean(change, na.rm = TRUE)) %>%
  ungroup()

data$label <- paste(data$name,"\n",round(data$meanC,0),sep="" )  

minYear = min(data$year)
maxYear = max(data$year)

#endpoint layer
Endpoints <- data %>% 
  group_by(name) %>%
  filter(year == max(year)) %>%
  select(year, name, n, label) %>%
  ungroup()
         
namePlot <- data %>%
  ggplot(mapping = aes(x=year, y=n)) +
  geom_line(aes(color=name), show.legend = FALSE) +
  coord_cartesian(xlim = c(minYear, maxYear+10)) +
  scale_color_ucscgb() +
  geom_point(data = Endpoints, size=1.5, shape=21,
            aes(color=name, fill=name), show.legend=FALSE) +
  geom_label_repel(data=Endpoints, aes(label=label),
                  color = c("forestgreen","red")[1+grepl("\\-\\d",Endpoints$label)],
                  show.legend = FALSE,
                  vjust = 0, xlim=c(maxYear+3,maxYear+10), size=3, direction='y')
         
print(namePlot)

它会生成下面的图

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标签的颜色由color = c("forestgreen","red")[1+grepl("\\-\\d",Endpoints$label)],控制，因此，在这种情况下，标签中具有正值的数据为绿色，具有负值的数据为红色。我想要的是使从端点到标签框的连接线与由geom_line(aes(color=name),show.legend = FALSE控制的数据线的颜色相同

在ggrepel文档中，有一个segment.color参数可以控制线段的颜色，但它不是美观的。所以看起来它必须是像segment.color="red"这样的“硬编码”，这对我没有真正的帮助。我也找到了关于这个问题的this discussion，似乎提出了一个解决方案，但我一直无法让它工作。问题的一部分是它涉及到scale_color_discrete(aesthetics = c("color", "segment.color"))，而我已经有了scale_color_ucscgb()，所以我收到了关于更换scales的警告……

任何指导都将不胜感激。

Answer 1

基于@aosmith的指导的工作版本

library(ggplot2)
library(babynames)
library(dplyr)
library(ggrepel)
library(ggsci)

data <- babynames %>%
  filter(name %in% c("Ashley", "Patricia", "Mary", "Minnie")) %>%
  filter(sex=="F")

data <- data %>% group_by(name) %>%
  mutate(change = n - lag(n)) %>% 
  mutate(meanC = mean(change, na.rm = TRUE)) %>%
  ungroup()

data$label <- paste(data$name,"\n",round(data$meanC,0),sep="" )  

minYear = min(data$year)
maxYear = max(data$year)

#endpoint layer
Endpoints <- data %>% 
  group_by(name) %>%
  filter(year == max(year)) %>%
  select(year, name, n, label) %>%
  ungroup()

namePlot <- data %>%
  ggplot(mapping = aes(x=year, y=n)) +
  geom_line(aes(color=name), show.legend = FALSE) +
  coord_cartesian(xlim = c(minYear, maxYear+15)) +
  geom_point(data = Endpoints, size=1.5, shape=21,
             aes(color=name, fill=name), show.legend=FALSE) +
  geom_label_repel(data=Endpoints, aes(label=label,
                                       segment.color=name),
                   color = c("forestgreen","red")[1+grepl("\\-\\d",Endpoints$label)],
                   show.legend = FALSE,
                   force = 50, 
                   vjust = 0, xlim=c(maxYear+5,maxYear+12), size=3, direction='y') +
  scale_color_discrete(aesthetics = c("color", "segment.color"))

print(namePlot)

产生

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