demo/signSTAT.R

In yihui/MSG: Data and Functions for the Book Modern Statistical Graphics

par(xaxt = "n", yaxt = "n", mar = c(2, 0.1, 3, 0.1))
y = seq(2 * pi, 0, length = 150)
x = sin(y)
plot(x, y,
  type = "n", xlim = c(-1.3, 1.3), ylim = c(-0.93, 7.21),
  xlab = "", ylab = "", main = "IN THE ORBIT OF STATISTICS", asp = 1
)
rx = seq(-2, 2, length = 300)
ry = dnorm(rx, 0, 0.2) + y[75]
rty = ry - y[75]
agl = pi / 4 + ifelse(rty / rx > 0, atan(rty / rx), atan(rty / rx) + pi)
r = sqrt(rx^2 + rty^2)
rtx = r * cos(agl)
rty = r * sin(agl) + y[75]
lines(rtx, rty)
segments(-0.45, y[75] - 0.45, 0.45, y[75] + 0.45, col = "white", lwd = 2)
q95 = qnorm(0.025, 0, 0.2)
d95 = dnorm(q95, 0, 0.2)
rg = rx > q95 & rx < -q95
polygon(c(rtx[rg][1], rtx[rg], rtx[rg][length(rg)]),
  c(rty[rg][1], rty[rg], rty[rg][length(rg)]),
  col = "lavender"
)
radius = ifelse(0.5 * abs(cos(y)) + 0.1 < 0.15, 0.15,
  0.5 * abs(cos(y)) + 0.1
)
symbols(x, y,
  circles = radius, inches = FALSE, fg = heat.colors(150),
  add = TRUE
)
idx = rep(c(TRUE, FALSE), 75)
segments(x[idx], y[idx], x[!idx], y[!idx], col = heat.colors(200)[1:150][idx])
arrows(x[1], y[1], x[1] + 0.75, y[1] + 0.75,
  col = "red", lwd = 2, angle = 75
)
arrows(x[150] - 0.75, y[150] - 0.75, x[150], y[150],
  col = "yellow", lwd = 2, angle = 75
)
mtext("``STAT'' made by Yihui XIE using R, School of Statistics, RUC, 2007",
  side = 1, cex = 0.8
)