在双重嵌套的lapply中为多条回归线添加颜色

# 创建示例数据
df <- data.frame(
  group = rep(LETTERS[1:3], each = 10),
  x = rep(1:10, 3),
  y = c(runif(10), runif(10) + 1, runif(10) + 2)
)

library(ggplot2)

# 创建绘图函数
plot_regression <- function(data) {
  # 拟合线性回归模型
  model <- lm(y ~ x, data = data)
  
  # 提取回归系数
  intercept <- coef(model)[1]
  slope <- coef(model)[2]
  
  # 绘制散点图和回归线
  p <- ggplot(data, aes(x = x, y = y)) +
    geom_point() +
    geom_abline(intercept = intercept, slope = slope, color = data$color) +
    labs(title = paste("Group", unique(data$group)))
  
  return(p)
}

# 为每个组生成一个颜色
colors <- c("red", "blue", "green")

# 使用lapply函数嵌套绘制回归线
plots <- lapply(unique(df$group), function(g) {
  subset <- df[df$group == g, ]
  subset$color <- colors[as.numeric(g)]
  plot_regression(subset)
})

# 显示所有的绘图
for (p in plots) {
  print(p)
}