连接点到中心点(2d散射点)

Question

我有两个dfs

df1 <- data.frame(x= seq(1,1000,1), y=rnorm(1000,500,250), z=rep(1:4,250))

df2 <- data.frame(x = c(450,481,512,571), y=c(450,481,512,571), z=1:4)

我把它们画成这样；

library(ggplot2)   
ggplot(df1) + 
      geom_point(aes(x=x,y=y,color = z),alpha=0.2) +
      geom_point(data = df2, aes(x=x,y=y,color = z),size=4)

我希望所有的x，y，对应于df1中的z=1，连接到x，y对应于df2中的z=1。这将从df2中的点创建某种类型的辐射线。我怎样才能做到这一点？

提前谢谢。

Answer 1

我将通过z对这两个数据帧进行左连接，然后使用geom_segment。将z着色为离散变量也可能更有意义：

df3 <- dplyr::left_join(df1, df2, by = "z", suffix = c("_1", "_2"))
  
ggplot(df3) + 
      geom_point(aes(x_1, y_1, color = factor(z)), alpha = 0.2) +
      geom_segment(aes(x_1, y_1, xend = x_2, yend = y_2, color = factor(z)),
                   alpha = 0.2) +
      geom_point(data = df2, aes(x, y, fill = factor(z)), size = 5,
                 color = "black", shape = 21) +
      theme_minimal()

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