在ggplot2堆疊條形圖中手動更改一個因子水平的顏色

Question

我正在做一個演講，並希望通過保留特定因子水平的顏色，同時在其他變量中使其他因子水平變灰的同時，突出顯示幻燈片中某一因子水平的發生率。

以vcd庫中的Arthritis數據集為例：

library(vcd)
ggplot(Arthritis, aes(x = Sex, fill = Improved)) + geom_bar(position = "fill")

例如，當我向聽眾介紹男性明顯改善的情況時，我是否可以保留該情節的某個版本，該版本保留男性明顯改善的顏色，但將其他所有顏色都灰顯呢？ 最好通過使用不同的灰色陰影來保留邊界？

Answer 1

考慮以下示例：

library(scales)
library(ggplot2)

ggplot(Arthritis)+
  geom_bar(aes(x = Sex, group = Improved), fill = c("red", "blue", "green", "yellow", "grey50", "black"), position = "fill")

要更改指定的字段，而其他字段則保留默認的ggplot顏色：

ggplot(Arthritis)+
  geom_bar(aes(x = Sex,
               group = Improved),
           fill = c(rev(hue_pal()(3)),
                    "black",
                    hue_pal()(3)[2:1]),
            position = "fill")

或用陰影將其余的部分變灰

ggplot(Arthritis)+
  geom_bar(aes(x = Sex,
               group = Improved),
           fill = c(paste0("grey", 7:9*10),
                    hue_pal()(3)[3],
                    paste0("grey", 8:9*10)),
           position = "fill")

要保留圖例，只需在您的初始圖層上繪制以上內容即可：

ggplot(Arthritis)+
  geom_bar(aes(x = Sex, fill = Improved),  position = "fill")+
  geom_bar(aes(x = Sex,
               group = Improved),
           fill = c(paste0("grey", 7:9*10),
                    hue_pal()(3)[3],
                    paste0("grey", 8:9*10)),
           position = "fill")

Answer 2

加

scale_fill_manual(values=c("Marked" = "RoyalBlue", "Some" = "DarkGrey", "None"="LightGrey"))

完整的ggplot調用：

ggplot(Arthritis, aes(x = Sex, fill = Improved)) + 
  geom_bar(position = "fill")+
  scale_fill_manual(values=c("Marked" = "RoyalBlue", "Some" = "DarkGrey", "None"="LightGrey"))

Answer 3

另一個選擇是用NA替換我們要突出顯示的數據點，然后使用scale_fill_grey為參數na.value 。 我們手動重新標記圖例以顯示原始名稱。

突出顯示所有已標記

 library(dplyr) ggplot(Arthritis %>% mutate(Improved = replace(Improved, Improved == "Marked", NA))) + geom_bar(position = "fill", aes(x = Sex, fill = Improved))+ scale_fill_grey(start = 0.8, end = 0.6, na.value = "RoyalBlue", labels = c("None", "Some", "Marked")) 

突出顯示男性標記

 ggplot(Arthritis %>% mutate(Improved = replace(Improved, Improved== "Marked" & Sex == "Male", NA))) + geom_bar(position = "fill", aes(x = Sex, fill = Improved))+ scale_fill_grey(start = 0.8, end = 0.2, na.value = "RoyalBlue", labels = c("None", "Some", "Marked", "Marked")) 

Answer 4

您可以添加一個包含顏色映射的列，並將其與scales_fill_identity() 。

reprex::reprex_info()
#> Created by the reprex package v0.1.1.9000 on 2017-11-18

library(vcd)
#> Loading required package: grid

lvls <- levels(Arthritis$Improved)
color_maps <- scales::grey_pal(start = 0.8, end = 0.9)(length(lvls))
names(color_maps) <- lvls


library(dplyr, warn.conflicts = FALSE)

Arthritis_w_fill <- Arthritis %>%
  mutate(
    fill = if_else(
      Sex == "Male" & Improved == "Marked",
      "blue",
      color_maps[Improved]
  )
)


library(ggplot2)

ggplot(Arthritis_w_fill, aes(x = Sex, fill = fill)) +
  geom_bar(position = "fill") +
  scale_fill_identity(guide = "legend",
                      breaks = c(color_maps, "blue"),
                      labels = c(lvls, 'Sex == "Male" & Improved == "Marked"'))