Analytical representation of stroboscopic maps of ordinary nonlinear differential equations

The stroboscopic map of some nonlinear dynamical systems can be described by means of a series expansion with only few non-trivial coefficients, provided that the frequency of the stroboscope coincides with the basic frequency of the oscillator. An analytic representation of such a 'simple' map can be obtained by the following two methods: (i) analytical integration of the ordinary differential equation, or (ii) numerical integration on a discrete grid scheme and subsequent approximation by an appropriate series of functions.