Figure 7

Sample stationary solution of Fitzhugh-Nagumo system with two morphogens in two spatial dimensions. Cases correspond to  R = - 0.04, - 0.02, - 0.01, 0, 0.01, 0.02, 0.04, from left to right. These cases correspond to the transition from inverted spots (R = -0.04, -0.02, -0.01) to labyrinths (R = 0) to spots (R = 0.01, 0.02, 0.04). All other simulation parameters D = 0.04, ϵ = 1, ρ = 0.3 are identical in all panels. Simulations were run until a numerical steady state was reached (maximum difference in any lattice point less than 1e-16, the machine epsilon). Total time until reaching steady states are shown above each case. The color bar included in the right side of the Figure applies to all panels identically.