Results obtained with 10,000 particles and discrepancy 2. With this large value for the discrepancy parameter, the model selection in (b) exhibits lower probability for larger models, and the two-dipole model has nonnegligible posterior probability but is never the mode of the distribution. The set of estimated dipoles is now smaller and contains only two activations, corresponding to Source 3 and 4, that is, the two dipoles producing the strongest field.
