# Reaction-diffusion system animation

I'm using following code to generate a picture of the reaction-diffusion process:

Explicit Euler method too slow for reaction-diffusion problem

I would like to obtain an animation effect. When I draw the solution step by step, it does give good animation. The problem is that the solution quickly converges to uniform, solid color (i.e. uniform concentration of chemical species).

How to sustain the animation? The solution should reverse the Euler method to some degree? Adding random noise sustains the animation, but also adds visible noise