new files

Task/Classes/R/classes-1.r

@@ -0,0 +1,13 @@
+#You define a class simply by setting the class attribute of an object
+circS3 <- list(radius=5.5, centre=c(3, 4.2))
+class(circS3) <- "circle"
+
+#plot is a generic function, so we can define a class specific method by naming it plot.classname
+plot.circle <- function(x, ...)
+{
+   t <- seq(0, 2*pi, length.out=200)
+   plot(x$centre[1] + x$radius*cos(t),
+      x$centre[2] + x$radius*sin(t),
+      type="l", ...)
+}
+plot(circS3)