An oscillation in a dynamical system can be easily localized numerically if initial conditions from its open neighborhood in the phase space (with the exception of a minor set of points of measure zero) lead to longtime behavior that approaches the oscillation. From a computational point of view, such an oscillation (or a set of oscillations) is called an attractor and its attracting set is called a basin of attraction (i.e., a set of initial data for which the trajectories numerically tend to the attractor).