  The far-infrared absorption of triangular and square two-dimensional quantum
dots is studied by means of time simulations of the density oscillations within
the time-dependent local-spin-density approximation. The absorption is
spatially analyzed using a local-response theory that allows the identification
of {\em corner} and {\em side} modes in the geometric nanostructures. The
evolution with a vertical magnetic field of varying intensity is also
discussed.
