  The Density of States Functional Fit Approach (DoS FFA) is a recently
proposed modern density of states technique suitable for calculations in
lattice field theories with a complex action problem. In this article we
present an exploratory implementation of DoS FFA for the SU(3) spin system at
finite chemical potential $\mu$ - an effective theory for the Polyakov loop.
This model has a complex action problem similar to the one of QCD but also
allows for a dual simulation in terms of worldlines where the complex action
problem is solved. Thus we can compare the DoS FFA results to the reference
data from the dual simulation and assess the performance of the new approach.
We find that the method reproduces the observables from the dual simulation for
a large range of $\mu$ values, including also phase transitions, illustrating
that DoS FFA is an interesting approach for exploring phase diagrams of lattice
field theories with a complex action problem.
