相关疑难解决方法(0)

这个问题来自早期的问题及其答案.

首先是一些玩具数据:

df = read.table(text = 
"School      Year    Value 
 A           1998    5
 B           1999    10
 C           2000    15
 A           2000    7
 B           2001    15
 C           2002    20", sep = "", header = TRUE)

最初的问题是如何为每所学校绘制价值年度线.答案或多或少对应于下面的p1和p2.但也要考虑p3.

library(ggplot2)

(p1 <- ggplot(data = df, aes(x = Year, y = Value, colour = School)) +       
   geom_line() + geom_point())

(p2 <- ggplot(data = df, aes(x = factor(Year), y = Value, colour = School)) +       
  geom_line(aes(group = School)) + geom_point())

(p3 <- ggplot(data = df, aes(x …