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+#############
+# Chapter 10.2 Mean and correlation functions
+
+## Example 10.5
+
+# R code for Example 10.5
+x = matrix(0, 1000, 20)
+t = seq(-2, 2, (2+2)/999)
+
+for (i in 1:20) {
+    x[,i] = runif(1) * cos(2 * pi * t)
+}
+
+matplot(t, x, lwd=2, col="gray")
+lines(t, 0.5*cos(2*pi*t), lwd=4, col="darkred")
+grid()
+