Gray-Scott Model at F 0.0180, k 0.0590  

These images and movie demonstrate the behavior of the Gray-Scott reaction-diffusion system with σ=Du/Dv=2 and parameters F=0.0180, k=0.0590.

Spots multiply by mitosis (generation interval of about 865 tu), remaining viable only if they continue to move forward. Any spots that become approximately circular will pulse a few times (with a period of about 225 tu) and then die out.    (glossary of terms)

             increase F

decrease k
after 90 tu
after 450 tu

15 frames/sec.; each fr. is 30 iter. steps = 15 tu; 1800 fr. total (27,000 tu)


after 1,650 tu after 6,750 tu after 27,000 tu
(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

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This page was written in the "embarrassingly readable" markup language RHTF, and was last updated on 2018 Aug 27. s.11