Figure 13. Schematic diagram showing the GGH representation of an index-copy attempt for two cells on a 2-dimensional square lattice.

The “white” pixel (source) of cell with attempts to replace the “grey” pixel (target) of cell with . The probability of accepting the index copy is given by equation (1). Bold lines denote boundaries of the cells. Pixel colour denotes cell type. Notice that in GGH simulations we typically have multiple cells with different id but belonging to the same type .