如何在ggpplot中合并图例

library(ggplot2)

# 创建一个示例数据集
data <- data.frame(
  x = c(1, 2, 3),
  y1 = c(1, 2, 3),
  y2 = c(2, 3, 4),
  y3 = c(3, 4, 5)
)

# 创建一个包含多个图例的ggplot图形
plot <- ggplot(data, aes(x = x)) +
  geom_line(aes(y = y1, color = "y1")) +
  geom_line(aes(y = y2, color = "y2")) +
  geom_line(aes(y = y3, color = "y3")) +
  labs(color = "Legend") +
  theme(legend.position = "bottom")

# 合并图例
plot <- plot +
  guides(color = guide_legend(override.aes = list(
    linetype = c(1, 1, 1),
    shape = c(16, 16, 16),
    color = c("red", "blue", "green"),
    size = c(1, 1, 1)
  )))

# 显示图形
plot