#Image and contour plots (These are Oooh-Ahhh plots)

data(volcano)
x <- 10 * (1:nrow(volcano))
x.at <- seq(100, 800, by = 100)
y <- 10 * (1:ncol(volcano))
y.at <- seq(100, 600, by = 100)
image(x, y, volcano, col = terrain.colors(100), axes = FALSE)

rx <- range(x <- 10*1:nrow(volcano))
ry <- range(y <- 10*1:ncol(volcano))
ry <- ry + c(-1,1) * (diff(rx) - diff(ry))/2
tcol <- terrain.colors(12)

par(mfrow=c(1,1))
opar <- par(pty = "s", bg = "lightcyan")
plot(x = 0, y = 0,type = "n", xlim = rx, ylim = ry, xlab = "", ylab = "")
u <- par("usr")
rect(u[1], u[3], u[2], u[4], col = tcol[8], border = "red")
contour(x, y, volcano, col = tcol[2], lty = "solid", add = TRUE)
title("A Topographic Map of Maunga Whau", font = 4)
abline(h = 200*0:4, v = 200*0:4, col = "lightgray", lty = 2, lwd = 0.1)