Gray–Scott model
A reaction–diffusion system heavily studied for its complex dynamics is the Gray–Scott system, given by
where we take
- Load the interactive simulation to explore the system.
A famous 1993 paper on this model explored a range of the parameters
- This classification simulation explores this approach, with
depending on in the range and depending on in the range .
Building from the previous simulation, we can rescale the heterogeneity to still be monotonic, but to use up more of the domain to see different dynamical regimes.
- Explore this in this rescaled simulation, where we also plot the variable
instead by default (you can click on to change this to plot instead). Here is another version of this rescaled model which also includes a porous-medium diffusion term (that is, ), which radically alters the parameter space as is increased from 1.
Interestingly, the value of
Furthermore, when
Below we’ve listed some parameter combinations that give rise to different and interesting behaviours.
One of our favourites is the moving spots simulation, which exhibits spots bobbing around.
- Initiate this motion and then increase
slowly to about . The spots become sparse and start exhibiting strange diversions in their motions.
Description | ||
---|---|---|
0.037 | 0.06 | Labyrinthine |
0.03 | 0.062 | Spots |
0.025 | 0.06 | Pulsating spots |
0.078 | 0.061 | Worms |
0.039 | 0.058 | Holes |
0.026 | 0.051 | Spatiotemporal chaos |
0.034 | 0.056 | Intermittent chaos/holes |
0.014 | 0.054 | Moving spots (glider-like) |
0.018 | 0.051 | Small waves |
0.014 | 0.045 | Big waves |
0.062 | 0.061 | U-skate world |