Forward-fitting synthetic STIX visibilities associated with configurations mimicking three non-thermal and three thermal emissions, by means of Simulated annealing, evolutionary algorithm and PSO. First column: simulated configurations (the values of the configuration parameters are given in Table 1). Considering the 25 realizations of STIX visibility sets already used in Table 1, the second, third and fourth columns show the kind of reconstruction most frequently provided by Simulated annealing, evolutionary algorithm, and particle swarm optimization, respectively.