將圖例添加到ggplot2

Question

我嘗試在我的ggplot2圖中添加一個圖例，但它沒有用完。 show.legend命令也不會改變任何東西

在這個問題的答案之后（ 在ggplot中添加手動圖例 ）我嘗試了scal_colour_manueal，但它沒有成功

library(ggplot2)
library(data.table)

color1 = "#D30F4B"
color2 = "#66B512"

data= data.frame(Week = rep(1:5,2), kpi = rep(c("Var1", "Var2"), each=5), value = runif(10), value2 = c(runif(5), rep(NA,5))  )

ggp <- ggplot( data = data, aes( x = Week, y = value, group = kpi) ) +
  geom_line(color=color1, show.legend = T) 

ggp <- ggp +
geom_line( mapping = aes( x = Week, y = value2, group = kpi), colour = color2 , show.legend = T) 

ggp <- ggp +  
  facet_wrap( kpi ~ . , ncol = 1) +
  scale_colour_manual(name="Legend", values=c(color1, color2))

plot(ggp)

如何在此圖中添加圖例？

Answer 1

如果您希望它們依賴於數據框的某個變量，則不應在aes之外設置顏色。

library(ggplot2)
library(data.table)

color1 = "#D30F4B"
color2 = "#66B512"

data= data.frame(Week = rep(1:5,2), kpi = rep(c("Var1", "Var2"), each=5), value = runif(10), value2 = c(runif(5), rep(NA,5))  )

ggp <- ggplot( data = data, aes( x = Week, y = value, col= kpi) ) +
  geom_line(show.legend = T) 

ggp <- ggp +
geom_line( mapping = aes( x = Week, y = value2, col= kpi), show.legend = T) 

ggp <- ggp +  
  facet_wrap( kpi ~ . , ncol = 1) +
  scale_colour_manual(name="Legend", values=c(color1, color2))

plot(ggp)

Answer 2

另一個暗示：當數據“整潔”時，ggplot效果最好（參見例如Hadley Wickham的R for Data Science ）。 然后解決方案看起來像這樣（ gather調用重新整形/整理數據，以便它更適合ggplot）：

library(tidyverse)
library(ggplot2)
library(data.table)

color1 = "#D30F4B"
color2 = "#66B512"

data= data.frame(Week = rep(1:5,2), kpi = rep(c("Var1", "Var2"), each=5), value = runif(10), value2 = c(runif(5), rep(NA,5))  )

data <- gather(data, key = value_name, value = value, -Week, -kpi) ## tidy the data with "gahter"

ggplot(data, aes(x = Week, y = value, colour = value_name, group = value_name)) +
    geom_line() +
    facet_wrap(kpi ~ ., ncol = 1) +
    scale_colour_manual(name="Legend", values=c(color1, color2))

Answer 3

我們可以有兩個geom_line各自的顏色，然后用facet_wrap

library(ggplot2)

ggplot(data) + 
  aes(x = Week, y = value2, group = kpi, colour = color2) +
  geom_line() +
  geom_line(aes( x = Week, y = value, group = kpi, color = color1)) + 
  facet_wrap( kpi ~ . , ncol = 1) +
  scale_colour_manual(name="Legend", values=c(color1, color2))