摘要: Abstract The paper deals with simple computations methods for the determination of nonlinearity a system from input/output records. so-called test should_ not require long computation time and has to be independent concrete nonlinear structure order linear dynamic part in process, i.e. basically nonparametric method is needed. following are presented: domain test, steady state output average value frequency method, spectral density correlation dispersion higher autocorrelation cross-correlation based on parameter estimation structure. different procedures shown at or feature first-and second linear, Hammerstein Wiener models.