Simulate the spatial component of the self-correcting model
sim_spatial_sc(M_n, params, nsim_t, xy_bounds)a matrix of point locations in the (x,y)-plane.
a vector of (x,y)-coordinates for largest point.
a vector of parameters (alpha_2, beta_2).
number of points to simulate.
vector of lower and upper bounds for the domain (2 for x, 2 for y).