outlets-config : enumerates all isomorphic graphs

outlets-clusters : groups patterns into clusters using
                   similar shapes for the configurations

outlets-eqp : compute equilibrium prices and market shares (locations are given)
              -- solve a linear system of equations --

outlets-eqx : compute optimum locations for a given location (prices are endogenous)
              -- find a fast procedure --

outlets-eq_test : test whether a locational setting is optimum
                  -- compute gradient at each outlet position --

outlets-graph : plot configurations

outlets-welf : compute market welfare corresponding to each config$
               -- equilibrium pricies and locations are given --