hk0413_Base graphics_inclass4

#
n <- 60
t <- seq(0, 2*pi, length=n)
x <- sin(t)
y <- cos(t)
#
par(pty = "s")
#
for (i in 1:n) {
  plot.new()
  plot.window(c(-1, 1), c(-1, 1))
  lines(x*y, -y, col="gray")
  points(x[i]*y[i], -y[i], pch=16,
  col=gray((i-1)/(n+1)))
  Sys.sleep(.05)
}

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