A higher order version of the Hopfield neural network is presented whi
ch will perform a simple vector quantisation or clustering function. T
his model requires no penalty terms to impose constraints in the Hopfi
eld energy, in contrast to the usual one where the energy involves onl
y terms quadratic in the state vector The energy function is shown to
have no local minima within the unit hypercube of the state vector so
the network only converges to valid final states. Optimisation trials
show that the network can consistently find optimal clusterings for sm
all, trial problems and near optimal ones for a large data set consist
ing of the intensity values from a digitised, grey-level image.