[en] A fit programme tested in the practice of reactor dynamics, how-ever applicable in general, is described. The parametrization is performed for either damped or undamped sinusoidal oscillations, which are present as a data table in form of distinct data. There-by it concerns, e.g. time-dependent state variables of reactor physics like neutron flux, power density, or xenon concentration in the reactor core. The parameters F₀, b, T, t₀, and anti F of the function F(t) = F₀ x exp ((b(t-t₀)) x sin ((t-t₀) x 2π/T) + anti F are computed iteratively of the data given distinctly by application of the method of the minimum least squares. An analogous algorithm and a subroutine written in PL/1 are introduced. The following properties of the programme are particularly useful for application: 1) The time-range for parametrization of a curve table is at all selectable. 2) The programme permeates an independent calculation of the starting data for the iteration. 3) An error analysis is performed after the successfully ended iteration. (orig.)