Müller-Lyer Wave

mlwave.r

library(grid)

o = function(th) {
  yd = -0.5
  grid.circle(0, 1, 0.25)
  grid.lines(c(0, 0), c(yd, 1-0.25))
  grid.lines(c(0, 0), c(yd, 0.5), gp = gpar(col="blue", lwd = 3))
  f = 0.25
  grid.lines(c(0, -cos(th)*f), c(0.5, 0.5+sin(th)*f), gp = gpar(lwd=3))
  grid.lines(c(0, +cos(th)*f), c(0.5, 0.5+sin(th)*f), gp = gpar(lwd=3))
  grid.lines(c(0, -cos(th)*f), c(yd, yd-sin(th)*f), gp = gpar(lwd=3))
  grid.lines(c(0, +cos(th)*f), c(yd, yd-sin(th)*f), gp = gpar(lwd=3))
}

d = function(offset) {
  grid.newpage()
  for (x in seq(0, 1, length.out = 17)) {
    pushViewport(viewport(x, 0.5, 0.1, 0.1))
    o(x*pi + offset)
    popViewport()
  }
  for (x in seq(0, 1, length.out = 17)) {
    pushViewport(viewport(x, 0.25, 0.1, 0.1))
    o(x*pi + offset-pi/3)
    popViewport()
  }
  for (x in seq(0, 1, length.out = 17)) {
    pushViewport(viewport(x, 0.75, 0.1, 0.1))
    o(x*pi + offset+pi/3)
    popViewport()
  }
}


library(animation)
saveGIF(
  {for (i in seq(0, pi*2*5, pi/10)) {d(i)}}, movie.name = "mlwave.gif",
  interval = 0.1,
  ani.width = 600,
  ani.heigth = 300
)