  Port-Hamiltonian (pH) systems are a very important modeling tool in almost
all areas of systems and control, in particular in network based model of
multi-physics multi-scale systems. They lead to remarkably robust models that
can be easily interconnected. This paper discusses the derivation of pH models
from time-domain input-output data. While a direct construction of pH models is
still an open problem, we present three different indirect numerical methods
for the realization of pH systems. The algorithms are implemented in MATLAB and
their performance is illustrated via several numerical examples.
