r - ggplot 每组仅包含一个观察值

Question

我正在尝试制作类似于此答案的情节:https://stackoverflow.com/a/4877936/651779

我的数据框如下所示:

df2 <- read.table(text='measurements samples value
1        4hours   sham1     6
2          1day   sham1   175
3         3days   sham1   417
4         7days   sham1   163
5        14days   sham1    37
6        90days   sham1   134
7        4hours   sham2     8
8          1day   sham2   402
9         3days   sham2   482
10        7days   sham2    67
11       14days   sham2    16
12       90days   sham2    31
13       4hours   sham3   185
14         1day   sham3   402
15        3days   sham3   482
16        7days   sham3    85
17       14days   sham3    29
18       90days   sham3    10',header=T)

并用

绘制它

ggplot(df2, aes(measurements, value)) + geom_line(aes(colour = samples))

图中没有显示线条，我收到消息

geom_path: Each group consist of only one observation. 
Do you need to adjust the group aesthetic?

我看不出我正在做的事情与上面链接的答案有什么不同。我应该改变什么才能使这项工作正常进行？

Answer 1

将group=samples添加到geom_line的aes中。这是必要的，因为您希望每个样本一行而不是每个数据点一行。

ggplot(df2, aes(measurements, value)) + 
  geom_line(aes(colour = samples, group = samples))