r - 将特定颜色分配给特定值

Question

这个问题在这里已经有了答案:

How to assign colors to categorical variables in ggplot2 that have stable mapping? (5 个回答)

关闭 7年前。

我要求 R 制作一系列情节。但是，ggplot2 分配给不同变量的颜色会因实际数据而异。我需要更多的一致性特别是我想要:

四是红色三要绿色两个是黄色的一个是白色的

根据以前的答案，我怀疑我需要订购关卡。有人可以帮帮我吗？

这里是一些示例数据:

df<-structure(list(`id` = structure(c(3L, 3L, 3L, 3L, 3L, 2L, 
                                  3L, 3L, 1L, 3L, 4L, 3L, 3L, 3L, 3L, 3L, 2L, 4L, 3L, 3L, 2L, 3L, 
                                  2L, 4L, 2L, 4L, 3L, 3L, 2L, 3L, 4L, 3L, 3L, 2L, 3L, 3L, 4L, 3L, 
                                  1L, 3L, 4L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L), .Label = c("ONE", 
                                                                                              "TWO", "THREE", "FOUR"), class = "factor"), NAME = c("0", "0.25", "0.5", 
                                                                                                                                          "0.75", "1", "1.25", "1.5", "1.75", "2", "2.25", "2.5", "2.75", 
                                                                                                                                          "3", "3.25", "3.5", "3.75", "4", "4.25", "4.5", "4.75", "5", 
                                                                                                                                          "5.25", "5.5", "5.75", "6", "6.25", "6.5", "6.75", "7", "7.25", 
                                                                                                                                          "7.5", "7.75", "8", "8.25", "8.5", "8.75", "9", "9.25", "9.5", 
                                                                                                                                          "9.75", "10", "10.25", "10.5", "10.75", "11", "11.25", "11.5", 
                                                                                                                                          "11.75", "12", "12.25")), .Names = c("id", "NAME"), row.names = c("0", 
                                                                                                                                                                                                                 "0.25", "0.5", "0.75", "1", "1.25", "1.5", "1.75", "2", "2.25", 
                                                                                                                                                                                                                 "2.5", "2.75", "3", "3.25", "3.5", "3.75", "4", "4.25", "4.5", 
                                                                                                                                                                                                                 "4.75", "5", "5.25", "5.5", "5.75", "6", "6.25", "6.5", "6.75", 
                                                                                                                                                                                                                 "7", "7.25", "7.5", "7.75", "8", "8.25", "8.5", "8.75", "9", 
                                                                                                                                                                                                                 "9.25", "9.5", "9.75", "10", "10.25", "10.5", "10.75", "11", 
                                                                                                                                                                                                                 "11.25", "11.5", "11.75", "12", "12.25"), class = c("tbl_df", 
                                                                                                                                                                                                                                                                     "tbl", "data.frame"))

代码如下:

library(ggplot2) 
library(tidyr)

colors <- c("red","white","yellow","green")


df$NAME <- rownames(df)

x<-gather(df,NAME)
colnames(x)<-c("Name", "variable","value")

ggplot(x, 
   aes(x = Name, y = variable, fill = factor(value))) + 
geom_tile() + 
scale_fill_manual(values=colors)+
scale_x_discrete(name="Time Period", limits= rownames(df))

Answer 1

正如您所说，您需要指定因子水平的顺序:

x$value = factor(x$value, levels = c("ONE", "TWO", "THREE", "FOUR"))
# the order of the vector you pass to levels defines the order of the factor

然后你需要以相同的顺序定义你的颜色向量。

# "FOUR to be red THREE to be green TWO to be yellow ONE to be white"
colors <- c("white","yellow","green","red")

另一种方法是命名颜色向量(如下)，但我更喜欢第一种方法。

colors <- c("red","white","yellow","green")
names(colors) = c("FOUR", "ONE", "TWO", "THREE")

colors
#  FOUR      ONE      TWO    THREE 
# "red"  "white" "yellow"  "green" 

无论哪种方式，您的绘图代码都应该可以正常工作。