Log likelihood surface. Log likelihood surface for parameters living on a restricted area of a two dimensional plane. For clarity, scale is not shown. Areas with low log-likelihood correspond to dynamics that do not fit the data at all, while areas with high log-likelihood fit the data very well. The surface shows multi-modality, plateaus and abrupt jumps which makes it difficult to sample from this density. When parameters do not live on a plane, these curses have even higher effect.