Hi, I just received wonderful assistance from Torsten an the others here in regards with solving with ODE45 the given ODE:
fun = @(x,y)[y(2);y(3);y(1)*(1-x^2)];
y0 = [1 0 1];
xspan = [-3 3];
[X,Y] = ode45(fun,xspan,y0);
If one wishes to solve this equation in a 2d disk (radial coodrdinates), which steps must one take?