no sinusoidal perturbation, the initial condition does not appear in the result, I could not figure out the problem.

I have problem that the initial condition fr = 0.05 +0.0001*(1+sin(k*x));fl,.. and the others did not show any sinusoidal perturbation. If I wrote the initial condition asfr = @(x) 0.05 +0.0001*(1+sin(k*x)); the code works. However if I delete @(x) d

oes not work.