ARX parameters from multiple-output models with variance information
Note: arxdata will be removed in a future release. Use polydata instead.
[A,B] = arxdata(m)
[A,B,dA,dB] = arxdata(m)
An idarx model object.
Also accepts single-output idpoly models with an underlying ARX structure with orders nc=nd=nf=0.
[A,B] = arxdata(m) returns A and B as 3-D arrays.
Suppose ny is the number of outputs (the dimension of the vector y(t)) and nu is the number of inputs.
A is an ny-by-ny-by-(na+1) array such that
A(:,:,k+1) = Ak A(:,:,1) = eye(ny)
B is an ny-by-nu-by-(nb+1) array with
B(:,:,k+1) = Bk
A(0) is always the identity matrix. The leading entries in B equal to zero, which means there are no delays in the model.
[A,B,dA,dB] = arxdata(m) returns A and B matrices, and dA and dB as the estimated standard deviations of A and B, respectively.
A and B are 2-D or 3-D arrays and are returned in the standard multivariable ARX format (see idarx), describing the model.
where Ak and Bk matrices have dimensions ny-by-ny and ny-by-nu, respectively. ny is the number of outputs (the dimension of the vector y(t)) and nu is the number of inputs.