气泡图

library(ggplot2)

set.seed(112)
mydata <- data.frame(x = 1:15, 
                      y = x + rnorm(15), 
                      z = c(1, 1, 1, 1, 1, 3, 3, 3, 3, 3, 5, 5, 5, 5, 5), 
                      g = rep(c("A", "B", "C"), 5)
)
mydata

ggplot(mydata, aes(x, y, fill = g, size = z)) + 
  geom_point(alpha = 0.5, shape = 21)

ggplot(mydata, aes(x, y, fill = g, size = z)) + 
  geom_point(alpha = 0.5, shape = 21, stroke = 1) + 
  scale_fill_brewer(type = "qual", palette = 2) + 
  scale_size_continuous(range = c(3, 10)) + 
  theme_classic()