ggplot2：如何通过多个变量为图形着色答案

【问题标题】：ggplot2: how to color a graph by multiple variablesggplot2：如何通过多个变量为图形着色
【发布时间】：2017-04-25 00:56:17
【问题描述】：

我相当肯定我在某处看到了解决方案，但由于我一直无法找到它，这就是我的问题。

我有一些由多个变量标识的时间序列数据，我希望能够使用 ggplot2 中的多个变量来绘制和区分颜色。

样本数据：

date <- c("2016-04-01 UTC", "2016-05-01 UTC", "2016-06-01 UTC", "2016-04-01 UTC",
          "2016-05-01 UTC", "2016-06-01 UTC", "2016-04-01 UTC", "2016-05-01 UTC",
          "2016-06-01 UTC", "2016-04-01 UTC")
temp <- c(80.24018,  85.88911, 104.23125,  85.13571,  91.21129, 104.88333,  97.81116,
          107.40484, 121.03958,  87.91830)
id <- c("A","A","A","A","A","B","B","B","B","B")
location <- c("N","S","S","N","N","S","N","S","N","S")

df <- data.frame(date,temp,id,location)

我的绘图尝试

library(ggplot2)

ggplot(df) + 
  geom_line(aes(x=date,y=temp,colour=factor(location), group=interaction(location,id)))

使用此代码仅按位置着色。我想将线条按位置和 ID 着色。

【问题讨论】：

ggplot(df, aes(as.Date(date), temp, color = id, linetype = location)) + geom_path()?或ggplot(df, aes(as.Date(date), temp, color = id:location)) + geom_line()，但读起来更容易混淆。

标签： r ggplot2

【解决方案1】：

两种选择：

library(ggplot2)

df <- data.frame(date = c("2016-04-01 UTC", "2016-05-01 UTC", "2016-06-01 UTC", "2016-04-01 UTC", "2016-05-01 UTC", "2016-06-01 UTC", "2016-04-01 UTC", "2016-05-01 UTC", "2016-06-01 UTC", "2016-04-01 UTC"),
                 temp = c(80.24018,  85.88911, 104.23125,  85.13571,  91.21129, 104.88333,  97.81116, 107.40484, 121.03958,  87.91830),
                 id = c("A","A","A","A","A","B","B","B","B","B"),
                 location = c("N","S","S","N","N","S","N","S","N","S"))

df$date <- as.Date(df$date)    # parse dates to get a nicer x-axis

将id 映射到颜色，将location 映射到线型：

ggplot(df, aes(date, temp, color = id, linetype = location)) + geom_path()

...或将所有交互绘制为不同的颜色：

ggplot(df, aes(date, temp, color = id:location)) + geom_path()

【讨论】：

【解决方案2】：

我想提供另一种方法。我不知道为什么但是 color=id:location 对我不起作用。我通过使用tidyr::unite解决了它

我就是这样做的：

library(ggplot2)

df <- data.frame(date = c("2016-04-01 UTC", "2016-05-01 UTC", "2016-06-01 UTC", "2016-04-01 UTC", "2016-05-01 UTC", "2016-06-01 UTC", "2016-04-01 UTC", "2016-05-01 UTC", "2016-06-01 UTC", "2016-04-01 UTC"),
                 temp = c(80.24018,  85.88911, 104.23125,  85.13571,  91.21129, 104.88333,  97.81116, 107.40484, 121.03958,  87.91830),
                 id = c("A","A","A","A","A","B","B","B","B","B"),
                 location = c("N","S","S","N","N","S","N","S","N","S"))

df$date <- as.Date(df$date) 

df <- tidyr::unite(df,"id_loc",id,location,remove = F)
ggplot(df,aes(date, temp, color = id_loc)) + geom_path()

plot generated

【讨论】：