  This paper focuses on the port-Hamiltonian formulation of systems described
by partial differential equations. Based on a variational principle we derive
the equations of motion as well as the boundary conditions in the well-known
Lagrangian framework. Then it is of interest to reformulate the equations of
motion in a port-Hamiltonian setting, where we compare the approach based on
Stokes-Dirac structures to a Hamiltonian setting that makes use of the involved
bundle structure similar to the one on which the variational approach is based.
We will use the Mindlin plate, a distributed parameter system with spatial
domain of dimension two, as a running example.
