使用 ggplot 定义图例

Question

我正在尝试在 R 中定义我的情节图例。

我有以下代码，这只是一个演示，真实数据将有 7-8 列和最多 20 个样本

library(ggplot2)
library(RColorBrewer)


colors <-brewer.pal(n = 3, name = 'Paired')

ids <- c("TestA", "TestB", "TestC")
bg <-c(23, 13, 15)
sample1 <- c(21,15,17)
sample2 <- c(27,25,11)
sample3 <- c(24,14,18)
df <- data.frame(ids, bg, sample1,sample2,sample3)

ggplot(df) + 
  geom_col(aes(x = ids, y = bg), size = 1, color = "grey", fill = "grey") +
  geom_point(aes(x = ids, y = sample1), size = 10, color=colors[1], group = 1) +
  geom_point(aes(x = ids, y = sample2), size = 10, color=colors[2], group = 1) +
  geom_point(aes(x = ids, y = sample3), size = 10, color=colors[3], group = 1)+ 
  ggtitle("Plot title") +
  xlab("x label") + ylab(" y label") +
  scale_colour_manual(values = c("95% PI"= "black",
                                  "Forecasts"  = "red",
                                  "Threshold" = "green"))

它产生以下输出

如何添加如下图的图例，并确保颜色匹配，即图例颜色匹配样本或背景颜色

Answer 1

这是你想要的吗？

ggplot(df) + 
  geom_col(aes(x = ids, y = bg, fill = "background"), size = 1, color = "grey") +
  geom_point(data = df %>% pivot_longer(cols = starts_with("sample"), names_to = "sample", values_to = "values"), aes(x = ids, y = values, color = sample), size = 10) +
  ggtitle("Plot title") +
  xlab("x label") + ylab(" y label") +
   scale_colour_manual(name = NULL, values = c("sample1"= "black",
                                 "sample2"  = "red",
                                 "sample3" = "green"),
                      labels = c("95% PI", "forecasts", "Threshold")) +
scale_fill_manual(name = NULL, values = c("background" = "grey"))