绘制来自两个data.frame的数据时图例的问题

# 导入所需的库
library(ggplot2)

# 创建两个data.frame
df1 <- data.frame(x = 1:10, y = rnorm(10), label = "Data 1")
df2 <- data.frame(x = 1:10, y = rnorm(10), label = "Data 2")

# 合并data.frame
df_combined <- rbind(df1, df2)

# 绘制数据
ggplot(df_combined, aes(x = x, y = y, color = label)) +
  geom_point() +
  scale_color_manual(values = c("Data 1" = "blue", "Data 2" = "red"))