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idPolynomial1D

Class representing single-variable polynomial nonlinear estimator for Hammerstein-Wiener models

Syntax

t=idPolynomial1D('Degree',n)
t=idPolynomial1D('Coefficients',C)
t=idPolynomial1D(n)

Description

idPolynomial1D is an object that stores the single-variable polynomial nonlinear estimator for Hammerstein-Wiener models.

You can use the constructor to create the nonlinearity object, as follows:

t=idPolynomial1D('Degree',n) creates a polynomial nonlinearity estimator object of nth degree.

t=idPolynomial1D('Coefficients',C) creates a polynomial nonlinearity estimator object with coefficients C.

t=idPolynomial1D(n) a polynomial nonlinearity estimator object of nth degree.

Use evaluate(p,x) to compute the value of the function defined by the idPolynomial1D object p at x.

idPolynomial1D Properties

After creating the object, you can use get or dot notation to access the object property values. For example:

% List all property values
get(p)
% Get value of Coefficients property
p.Coefficients
Property NameDescription
Degree

Positive integer specifies the degree of the polynomial
Default=1.

For example:

idPolynomial1D('Degree',3)
Coefficients

1-by-(n+1) matrix containing the polynomial coefficients.

FreeOption to fix or free the values in the mapping object. When you set Free to false, the object does not update during estimation.

Examples

Use idPolynomial1D to specify the single-variable polynomial nonlinearity estimator in Hammerstein-Wiener models. For example:

m=nlhw(Data,Orders,idPolynomial1D('deg',3),[]);

where 'deg' is an abbreviation for the property 'Degree'.

Tips

Use idPolynomial1D to define a nonlinear function y=F(x), where F is a single-variable polynomial function of x:

F(x)=c(1)xn+c(2)x(n1)++c(n)x+c(n+1)

Compatibility Considerations

expand all

Not recommended starting in R2021b

See Also

Introduced in R2007b