在使用ggplot的多个图中，图例中的几何点大小相等

library(ggplot2)

# 创建一个数据框
data <- data.frame(
  x = c(1, 2, 3, 4, 5),
  y = c(1, 4, 9, 16, 25),
  group = c("A", "A", "B", "B", "C")
)

# 创建一个散点图，点的大小相等
scatter_plot <- ggplot(data, aes(x = x, y = y, color = group)) +
  geom_point(size = 5, shape = 16) +
  scale_color_manual(values = c("red", "blue", "green")) +
  theme(legend.position = "bottom")

scatter_plot