  This article presents a new spectral analysis approach for dispersion error
and a methodology to numerically evaluate it. In practice, this new analysis
allows the numerical study of dispersion errors on all types of mesh and for
multiple dimensions. Nonetheless, when mesh uniformity and one-dimensionality
assumptions are imposed as in the classical method, the results of this new
technique coincide with those of the classic method. We establish the
theoretical basis of the approach, derive a numerical methodology to evaluate
dispersion errors and assess the method after a set of numerical tests on
non-uniform stretched meshes.
