ggplot2_氣泡圖

library(ggplot2)
plotdata <- data.frame(V1 = c(1:10),
                       V2 = c(1:10),
                       V3 = c(rnorm(10))*10)
ggplot(data = plotdata, aes(x = V1, y = V2, size = V3))+
  geom_point( alpha = 0.2, fill = "blue",shape = 21)+
  theme(axis.title=element_blank(), 
        axis.text=element_blank(), 
        axis.ticks=element_blank())+ 
  guides(fill = FALSE, color = FALSE, linetype = FALSE, shape = FALSE, size = FALSE)  #刪除圖例