There are 3 applet to illustrate the algorithms saw in the tutorial:
Here, a mini-applet to see how the problem of slope selection is quite huge. To see it, draw n points and ask to draw all the possible lines ("n choose 2").
Here, an applet to see how work the Shallow selection with sweeping. To see it, draw n lines and ask to select the kth x-coord (rank). Then start the sweeping line. We will able to see the inserted points, z' and z'', and a window shows all data about the work of the algorithm.
Applet with the general selection algorithm (we use the flow control but not the approximate rank). We this applet we ca see the idea of inversions to see the rank, and the idea of flow control to compute the relatif position in a constant time.