polydata
Access polynomial coefficients and uncertainties of identified model
Syntax
[A,B,C,D,F] = polydata(sys)
[A,B,C,D,F,dA,dB,dC,dD,dF]
= polydata(sys)
[___] = polydata(sys,J1,...,JN)
[___] = polydata(___,'cell')
Description
[
returns the coefficients of the polynomials A,B,C,D,F
] = polydata(sys
)A
, B
,
C
, D
, and F
that describe
the identified model sys
. The polynomials describe the
idpoly
representation of sys
as
follows.
For discretetime
sys
:$$A\left({q}^{1}\right)y\left(t\right)=\frac{B\left({q}^{1}\right)}{F\left({q}^{1}\right)}u\left(tnk\right)+\frac{C\left({q}^{1}\right)}{D\left({q}^{1}\right)}e\left(t\right).$$
u(t) are the inputs to
sys
. y(t) are the outputs. e(t) is a white noise disturbance.For continuoustime
sys
:$$A\left(s\right)Y\left(s\right)=\frac{B\left(s\right)}{F\left(s\right)}U\left(s\right){e}^{\tau s}+\frac{C\left(s\right)}{D\left(s\right)}E\left(s\right).$$
U(s) are the Laplace transformed inputs to
sys
. Y(s) are the Laplace transformed outputs. E(s) is the Laplace transform of a white noise disturbance.
If sys
is an identified model that is not an
idpoly
model, polydata
converts
sys
to idpoly
form to extract the polynomial
coefficients.
[
also returns the uncertainties A,B,C,D,F
,dA,dB,dC,dD,dF
]
= polydata(sys
)dA
, dB
,
dC
, dD
, and dF
of each of
the corresponding polynomial coefficients of sys
.
[___] = polydata(
returns the polynomial coefficients for the sys
,J1,...,JN
)J1,...,JN
entry in the
array sys
of identified models.
[___] = polydata(___,'cell')
returns all
polynomials as cell arrays of double vectors, regardless of the input and output
dimensions of sys
.
Input Arguments

Identified model or array of identified models. 

Indices selecting a particular model from an Ndimensional array

Output Arguments

Polynomial coefficients of the
Each entry in a cell array is a row vector that contains the coefficients of the corresponding polynomial. The polynomial coefficients are ordered the same way as the SISO case. 

Uncertainties in the estimated polynomial coefficients of
Each entry in 
Examples
Version History
Introduced before R2006a