如何在R中的矩阵中绘制随机点

Question

我需要绘制一组点数是一个5x5网格。 基本上，我需要绘制一组2点（可以是水平或垂直的），而另外3个点是一个5x5网格。

这些点的位置应随机归因。

最后，它看起来应该像这样（我可以在“静态”代码中做，但我不能以随机的atributtion做到这一点）

 par(xaxs = "i", yaxs = "i")
 plot.new()
 plot.window(xlim = c(0.5, 5.5), ylim = c(0.5, 5.5))
 grid(nx = 5, ny = 5, col = "black", lty = "dashed")
 box(lwd = 1)
    
 # PLot points 
 points(1, 5, pch = 16, col = "blue", cex = 1.5)
 points(2, 5, pch = 16, col = "blue", cex = 1.5)
       
 points(1, 1, pch = 16, col = "pink", cex = 1.5)
 points(1, 2, pch = 16, col = "pink", cex = 1.5)
 points(1, 3, pch = 16, col = "pink", cex = 1.5)

Answer 1

此功能将执行算法。通过列举所有可能有效的蓝点（只有40对）和有效的粉红色点（只有30个）来做到这一点。然后，它采样了一组有效的蓝点，然后反复采样随机的粉红色点，直到没有冲突为止。然后，它使用您的绘图代码绘制结果：

random_points <- function() {
  
  blue_pos <- cbind(c(1:20, c(1:25)[-c(5, 10, 15, 20, 25)]),
                    c(6:25, c(1:25)[-c(1, 6, 11, 16, 21)]))
  
  pink_pos <- cbind(c(1:15, 1:3, 6:8, 11:13, 16:18, 21:23),
                c(6:20, 2:4, 7:9, 12:14, 17:19, 22:24),
                c(11:25, 3:5, 8:10, 13:15, 18:20, 23:25))
  
  blue <- pink <- blue_pos[sample(nrow(blue_pos), 1),]
  
  while(any(pink %in% blue)) pink <- pink_pos[sample(nrow(pink_pos), 1),]
  
  par(xaxs = "i", yaxs = "i")
  plot.new()
  plot.window(xlim = c(0.5, 5.5), ylim = c(0.5, 5.5))
  grid(nx = 5, ny = 5, col = "black", lty = "dashed")
  box(lwd = 1)
  
  for(i in 1:2)  points(1 + (blue[i] - 1) %% 5, 
                        1 + (blue[i] - 1) %/% 5, 
                        pch = 16, col = "blue", cex = 1.5)
  
  for(i in 1:3) points(1 + (pink[i] - 1) %% 5,
                       1 + (pink[i] - 1) %/% 5,
                       pch = 16, col = "pink", cex = 1.5)
}

随机测试9次给我们：

par(mfrow = c(3, 3))
for(i in 1:9) random_points()