Why didn't Turing instability occur?

Why isn't Turing instability occurring even though the conditions for it are met at these parameters? I feel it's not quite reasonable. Could I have made a mistake somewhere?

Answer 1

[Abhimenyu]

Hi Bode,

I understand that you want to check Turing instability using your code. It is my understanding that in your file, “turing_condition.m”, the formula for “H2” is wrong. For Turing instability with diffusion, “H2” <0. The correction is as follows:

function [H1,H2]=turing_condition(d1,d2,jaco_matrix) 
j=jaco_matrix; 
H1=(d1)*(j(2,2))+(d2)*(j(1,1)); 
H2=(-(H1)^2)+4*(d1)*(d2)*(det(j)); 

This gives “H2” <0 which shows Turing instability. Follow the link on Turing conditions for better understanding,

https://genecompute.medium.com/deriving-the-conditions-for-turing-patterns-3496b7fa1e1a

Thank you,

Abhimenyu