基于部分匹配变量名的ggplot颜色

library(ggplot2)

# 创建一个数据框
df <- data.frame(
  variable = c("var1", "var2", "var3", "var4"),
  value = c(10, 20, 30, 40)
)

# 定义颜色映射表
color_mapping <- c(
  var1 = "red",
  var2 = "blue",
  var3 = "green"
)

# 绘制散点图
ggplot(df, aes(x = variable, y = value, color = variable)) +
  geom_point(size = 3) +
  scale_color_manual(values = color_mapping, 
                     guide = guide_legend(title = "Variable")) +
  labs(title = "Scatter Plot", x = "Variable", y = "Value")