Principal Mode Analysis

PMA
Computes the principal dynamic modes of a 2nd order nonlinear system using its 1st and 2nd order kernels, via eigen-decomposition.

PLM
Computes the principal dynamic modes of a 2nd-order nonlinear system using its Laguerre coefficients, via eigen-decomposition.

NLFIT
Estimates the polynomial/multinomial static non-linearities of specified principal modes for given input-output data.

NLMOD
Computes the model prediction for given principal modes and the associated static non-linearities (estimated by NLFIT).

PMN
Computes a 3-D surface corresponding to the nonlinearity of two specified principal mode outputs.

PMNRES
Computes the model prediction for two given principal modes and the static nonlinearity obtained by PMN.