Finish examples 10.11

ch10.r

@@ -58,5 +58,24 @@ for (i in 1:ncol(x)) {
 }
 stem(t, 1/(t+1), col="darkred", lwd=2, pch=1, type="o")
 
+## Example 10.11
 
+# R code for Example 10.11: Plot the time function
+t = seq(-2, 2, len = 1000)
+x = matrix(0, 1000, 20)
+
+for (i in 1:20) {
+    x[,i] = runif(1) * cos(2*pi*t)
+}
+
+matplot(t, x, lwd=2, col="gray", type="l", lty="solid", xaxp=c(-2,2, 8))
+grid()
+lines(t, 0.5*cos(2*pi*t), lwd=5, col="darkred")
+points(numeric(20), x[501,], lwd=2, col="darkorange")
+points(numeric(20) + 0.5, x[626,], lwd=2, col="blue", pch=4)
+
+# R code for Example 10.11: Plot the autocorrelation function
+t = seq(-1, 1, len=1000)
+R = (1/3)*outer(cos(2*pi*t), cos(2*pi*t))
+image(t, t, R, col=topo.colors(255), xlab="t_1", ylab="t_2")