The parameters are as follows:

1. a, b, eta are parameters of the equation.
2. delta is a "small" parameter that sets when a simplified iteration scheme is used that is good only for small values of one of the fields (the scheme is used when the value is less than delta). Increasing delta to 10^-2 increases the speed at the cost of faithfulness to the original equations.
3. amp is the amplitude of a sinusoidal forcing at one corner with frequency 0.5
4. speed is a benign way of increasing the speed at the cost of jerkiness of the plotting: the iteration is done speed times between each plot update.
5. The two choices of plot type show the concentrations of the two components involved in the reaction.

The system size is 64 along each edge. The mesh size h for the finite difference code is 0.5 and the time step dt=0.05.