复制 R 食谱中的示例时 scale_colour_discrete 不起作用

Question

我试图在R Cookbook 复制一个示例，该示例在图例中指定颜色和形状。

原代码是

# A different data set
df2 <- data.frame(
  sex = factor(c("Female","Female","Male","Male")),
  time = factor(rep(c(1,2),2), levels=c(1,2)),
  total_bill = c(13.53, 16.81, 16.24, 17.42)
)

# A basic graph
ggplot(data=df2, aes(x=time, y=total_bill, group=sex, shape=sex)) + 
  geom_line() + 
  geom_point() +
  scale_colour_discrete(name  ="Payer",
                          breaks=c("Female", "Male"),
                          labels=c("Woman", "Man")) +
  scale_shape_discrete(name  ="Payer",
                       breaks=c("Female", "Male"),
                       labels=c("Woman", "Man"))

我不想要这条线，所以我注释掉了geom_line()+ 部分。点不再有颜色。有人可以帮忙吗？

# A different data set
df2 <- data.frame(
  sex = factor(c("Female","Female","Male","Male")),
  time = factor(rep(c(1,2),2), levels=c(1,2)),
  total_bill = c(13.53, 16.81, 16.24, 17.42)
)

# A basic graph
ggplot(data=df2, aes(x=time, y=total_bill, group=sex, shape=sex)) + 
#  geom_line() + 
  geom_point() +
  scale_colour_discrete(name  ="Payer",
                          breaks=c("Female", "Male"),
                          labels=c("Woman", "Man")) +
  scale_shape_discrete(name  ="Payer",
                       breaks=c("Female", "Male"),
                       labels=c("Woman", "Man"))

Answer 1

您的两个代码块都缺少colour 美学，这将需要根据分类变量为您的几何图形着色。

您还可以简化代码：使用colour 美学或删除线条几何形状使group 美学变得多余：

# A different data set
df2 <- data.frame(
  sex = factor(c("Female","Female","Male","Male")),
  time = factor(rep(c(1,2),2), levels=c(1,2)),
  total_bill = c(13.53, 16.81, 16.24, 17.42)
)
library(ggplot2)
# A basic graph
ggplot(data=df2, aes(x=time, y=total_bill, shape=sex, colour=sex)) + 
  # geom_line() + 
  geom_point() +
  scale_colour_discrete(name  ="Payer",
                        breaks=c("Female", "Male"),
                        labels=c("Woman", "Man")) +
  scale_shape_discrete(name  ="Payer",
                       breaks=c("Female", "Male"),
                       labels=c("Woman", "Man"))

^{由reprex package (v0.3.0) 于 2020 年 12 月 16 日创建}