mdbtxt1
mdbtxt2
Proceed to Safety

Gray-Scott Model at F 0.0740, k 0.0650    

These images and movie demonstrate the behavior of the Gray-Scott reaction-diffusion system with σ=Du/Dv=2 and parameters F=0.0740, k=0.0650.

Solitons are the only viable pattern (a short worm, left of center, is seen shrinking into a soliton; the same happens with longer worms). Pairs of solitons in close proximity drift apart very slowly; drift speed diminishes exponentially with distance.

Categories: Munafo ν; Wolfram 2      (glossary of terms)

                increase F   









      
decrease k
      
after 756 tu
after 3,780 tu

15 frames/sec.; each fr. is 252 iter. steps = 126 tu; 1800 fr. total (226,800 tu)









      
increase k
      
after 13,860 tu after 56,700 tu after 226,800 tu
                decrease F   
(Click on any image to magnify)

In these images:

Wavefronts and other moving objects have decreasing u values (brighter color) on the leading edge of the blue part of the moving object, and increasing u (light pastel color) on the trailing edge. This is true even for very slow-moving objects — thus, you can tell from the coloring what direction things are moving in.

''tu'' is the dimensionless unit of time, and ''lu'' the dimensionless unit of length, implicit in the equations that define the reaction-diffusion model. The grids for these simulations use Δx=1/143 lu and Δt=1/2 tu; the system is 3.2 lu wide. The simulation meets itself at the edges (periodic boundary condition); all images tile seamlessly if used as wallpaper.

Go back to Gray-Scott pattern index


Robert Munafo's home pages on AWS    © 1996-2024 Robert P. Munafo.    about    contact
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. Details here.

This page was written in the "embarrassingly readable" markup language RHTF, and was last updated on 2015 Nov 07. s.27