


Wackermann calculates the global field strength SIGMA, the global
frequency PHI and a measure of spatial complexity OMEGA [1].
A stationary and a time-varying (adaptive) estimator is implemented
[SIGMA,PHI,OMEGA] = wackermann(...)
[...] = wackermann(S,0)
calculates stationary Wackermann parameter
[...] = wackermann(S,UC) with 0<UC<1,
calculates time-varying Wackermann parameter using
exponential window
[...] = wackermann(S,N) with N>1,
calculates time-varying Wackermann parameter using
rectangulare window of length N
[...] = wackermann(S,B,A) with B>=1 oder length(B)>1,
calulates time-varying Wackermann parameters using
transfer function B(z)/A(z) for windowing
S data (each channel is a column)
UC update coefficient
B,A filter coefficients (window function)
Remark: estimating of Omega requires the eigenvalues, the adaptive estimator
utilized the adaptive eigenanalysis method [2].
see also: TDP, BARLOW, HJORTH
REFERENCE(S):
[1] Jiri Wackermann, Towards a quantitative characterization of
functional states of the brain: from the non-linear methodology to the
global linear descriptor. International Journal of Psychophysiology, 34 (1999) 65-80.
[2] Bin Yang, Projection approximation subspace tracking.
IEEE Trans. on Signal processing, vol. 43, no. 1 jan. 2005, pp. 95-107.
[3] Saito N., Kuginuki T., Yagyu T., Kinoshita T., Koenig T., Pascual-Marqui
R. D., Kochi K., Wackermann J., and Lemann D., 1998.
Global, regional and local measures of complexity of multichannel EEG in acute, neurolepticnaive,
first-break schizophrenics. Society of Biological Psychiatry. 43:794–802.