attila wants checkerboard initial conditions

[gszep]

A systematic way of probing the dynamics of the approximate majority network is required. During a meeting on 17/01/18 we came up with a desirable initial condition: the checkerboard pattern, with the following parameters The above figure has X,Y initialised according to a given local population ratio, in checkerboard spatial pattern. The blank intermediate state is initialised B = 1 in the margins between squares. Perhaps the space of parameters should be restricted such that the global populations of X,Y are equal.

[gszep]

With the most recent commit I found that the periodic boundary conditions as implemented by the texture.wrapS and texture.wrapT breaks the symmetry of the initial condition.. this shouldn't happen.. perhaps because the gradients are not propagated correctly across the boundary?

• This bug has been resolved by commit 1b65dfd350ae52663f381e7badd88ba41f639d0e where I used fract() inside the GLSL code to wrap texture coordinates. In principle I could also intervene there to implement zero flux boundaries.. perhaps not now

[gszep]

Initial experiments show counterintuitive results: the faster diffusing chemical loses the approximate majority battle. As shown below the blue morphogen diffuses faster, but eventually is dominated by the yellow. This seems to be a general feature of the dynamics, not a function of initial condition. This is interesting enough to start another issue #13