一个比较啰嗦的π的模拟。运用投飞镖法计算圆周率。貌似程序可以写的更简洁些。 require(plotrix)
require(grid)

simp <- function(n){
  x <- runif(n)
  y <- runif(n)
  xy <- x^2 + y^2
  ind <- xy <=1
  ind2 <- ind+1
  up <- length(xy[which(xy <= 1)])
  pai <- up /n * 4
  plot(c(0, 1), c(0, 1), type = 'n', asp = 1,
    main = c('pi = ', paste(pai)))
  rect(0, 1, 1, 0)
  draw.circle(0, 0, 1)
  points(x, y, pch = 20, cex = .5,
    col = c('red', 'blue')[ind2])
}
simp(10)
simp(100)
simp(500)
simp(1000)
simp(2000)
simp(10000)