  The main goal of this work is to provide a description of the {trace per unit
volume} in terms of the {Dixmier trace} (regularized by the resolvent of the
harmonic oscillator) for a large class of two-dimensional \emph{magnetic
operators} perturbed by (homogeneous) {potentials}. One of the payoffs of this
result is the possibility of reinterpreting the {density of states} (DOS) of
these perturbed magnetic systems via the {Dixmier trace}, and taking advantage
of the fact that this quantity can be conveniently calculated on the basis of
the Laguerrre functions that diagonalize the harmonic oscillator.
