Here are some supplemental notes for Chapter 2.  

Two main programs are provided:

pde_1_main.m      Main program in Chapter 2 as discussed with Listing 2.2

pde_1a_main.m     pde_1_main.m with additional composite plots as discussed with
                  Listing 2.2a 

pde_1.m           Execution of either main program with mf=1 calls this ODE
                  routine (from ode15s)

pde_2.m           Execution of either main program with mf=2 calls this ODE
                  routine (from ode15s)

pde_3.m           Execution of either main program with mf=3 calls this ODE
                  routine (from ode15s)