The code kdv solves the KdV equation
                   u_t + uu_x +gamma*u_xxx = 0
using a pseudo spectral method.  It uses the function mfile wwprime.m
as the right-hand side of the system of ODE's.  Initial data must be
provided in a function mfile f.m

    The calls for ode45 are slightly different in MATLAB 4.2 and in 
MATLAB 5.0. The line in program kdv.m must be changed to agree
with the version you are using.