  Evaluation of global thermodynamic properties, such as the entropy or the
free energy, of complex systems featuring a high degree of frustration or
disorder is often desirable. Nevertheless, they cannot be measured directly in
standard Monte Carlo simulation. Therefore, they are either evaluated
indirectly from the directly measured quantities, for example by the
thermodynamic integration method (TIM), or by applying more sophisticated
simulation methods, such as the Wang-Landau (WL) algorithm, which can directly
sample density of states. In the present investigation we compare the
performance of the WL and TIM methods in terms of calculation of the entropy of
an Ising antiferromagnetic system on a Kagome lattice - a typical example of a
complex spin system with high geometrical frustration resulting in a non-zero
residual entropy the value of which is exactly known. It is found that in terms
of accuracy the implementationally simpler TIM can deliver results comparable
with the more involved WL method.
