  This paper is devoted to a discussion of the Discrete Fourier Transform (DFT)
representation of a chaotic finite-duration sequence. This representation has
the advantage that is itself a finite-duration sequence corresponding to
samples equally spaced in the frequency domain. The Fast Fourier Transform
(FFT) algoritm allows us an effective computation, and it can be applied to a
relatively short time series. DFT representation requirements were analized and
applied for determining the order-chaos transition in a nonlinear system
described by the equation $x[n+1]=rx[n](1-x[n])$. Its effectiveness was
demonstrated by comparing the results with those obtained by calculating the
largest Lyapounov exponent for the time series set, obtained from the logistic
equation.
