  The quantitative determination of the order-chaos transition in a nonlinear
dynamical system described by H\'enon mapping defined as
$x[n+1]=1.0-A*x[n]^2+B*y[n], y[n+1]=B*x[n]$, where $B=0.3$, and $A$ is an
adjustable control parameter, was made. This was achieved by applying the
Inverse Average Magnitude-Squared Coherence Index (IAMSCI). This method is
based on the Welch average periodogram technique and it has the advantage
respect to nonlinear dynamical methods that it may be applied to any stationary
signal by using discrete Fourier transform (DFT) representation which allows to
operate on a short discrete-time series. Its effectiveness was demonstrated by
comparing the results obtained by applying IAMSCI method with those obtained by
calculating the largest Lyapounov exponent (LLE), both applied to the same
discrete-time series set derived from the H\'enon mapping.
