Undefined function or variable "na".

God morning, I try start model Kohonen combine ARMA but in file armax.m occured error Undefined function or variable "na".It is error is in line ni =max([ na nb+nk-1 nc ]); I can do handler function but is error Unexpected MATLAB expression.

function th=armax(z,nn,maxiter,tol,lim,maxsize,Tcap) %ARMAX Computes the prediction error estimate of an ARMAX model. % % TH = armax(Z,NN) % % TH: returned as the estimated parameters of the ARMAX model % A(q) y(t) = B(q) u(t-nk) + C(q) e(t) % along with estimated covariances and structure information. % For the exact format of TH, see HELP THETA. % % Z : The output-input data Z=[y u], with y and u being column vectors. % For a time-series, Z=y only. The routine does not work for multi- % input systems. Use PEM for that case. % % NN: Initial value and structure information. When no initial parameter % estimates are available enter NN as % NN=[na nb nc nk], the orders and delay of the above model,or as % NN=[na nc] for the time-series case (ARMA-model). With an initial % estimate available in THI, a theta matrix of standard format, enter % NN=THI. Then the criterion minimization is initialized at THI. % % Some parameters associated with the algorithm are accessed by % TH = armax(Z,NN,maxiter,tol,lim,maxsize,T) % See HELP AUXVAR for an explanation of these and their default values.

% L. Ljung 10-1-86,12-09-91 % Copyright (c) 1986-92 by the MathWorks, Inc. % All Rights Reserved.

% % * Set up default values * [nz, Ncap]=size(z); [nr,cc]=size(nn); nu=nz-1; maxsdef=idmsize(Ncap);

if nargin<7, Tcap=[];end if nargin<6, maxsize=[];end if nargin<5, lim=[];end if nargin<4, tol=[];, end if nargin<3, maxiter=[]; end if isempty(Tcap),if nr>1,Tcap=gett(nn);else Tcap=1;end,end if isempty(maxsize),maxsize=maxsdef;end if isempty(lim),lim=1.6;end,if isempty(tol),tol=0.01;end if isempty(maxiter),maxiter=10;end if Tcap<0,Tcap=1;end, if maxsize<0,maxsize=maxsdef;end, if lim<0,lim=1.6;end if tol<0,tol=0.01;end,if maxiter<0, maxiter=10;end

% * Do some consistency tests *

%if nz<Ncap, error('The data should be organized in column vectors') %return,end %if nu<1, error('This routine only works for single-input systems. Use PEM instead!') %return,end %if nr==1 & cc~=2*nu+2, % disp('Incorrect number of orders specified:') % disp('For a time series nn=[na nc]') % disp('For a SISO system nn=[na nb nc nk]') % error('see above') %return,end

% * if nn has more than 1 row, it is a theta matrix % and we jump directly to the minimization * % if nr>1, nu=nn(1,3); if nu>1, error('This routine only works for single input systems. Use PEM instead') return,end if nu==1, na=nn(1,4);nb=nn(1,5);nc=nn(1,6);nk=nn(1,9); else na=nn(1,4);nb=0;nc=nn(1,5);nk=0;end n=na+nb+nc; t=nn(3,1:n).'; if nc>0, c=[1 t(na+nb+1:n).'];else c=1;end if na>0,a=[1 t(1:na).'];else a=1;end if nb>0,b=[zeros(1,nk) t(na+1:na+nb).'];else b=0;end ni=max([na nb+nk-1 nc]); e=pefilt(a,c,z(:,1)); if nu==1, e=e-pefilt(b,c,z(:,2),e(1:ni));end end if nr==1, if nu==0, na=nn(1); nc=nn(2); nb=0; nk=0; n=na+nc; v=z; narx=na; nd=na; end if nu==1, na=nn(1); nb=nn(2); nc=nn(3); nk=nn(4); n=sum(nn(1:3)); narx=[na nb nk]; nd=0; end ni =max([ na nb+nk-1 nc ]); HERE IS ERROR t=arx(z, narx, maxsize, Tcap ,0); if na>0, a=[1 t(1:na).'];else a=1;end if nb>0, b=[zeros(1,nk) t(na+1:na+nb).'];end if nc==0 % then we use the arx-estimate for initial condition e=pefilt(a,[1],z(:,1)); if nu==1, e=e-pefilt(b,[1],z(:,2),e(1:ni));end c=1; end

   if nc>0 %then we compute the IV-estimate in case nu==1
      if nu==1
         a=fstab(a);
         t=iv(z,narx,a,b,maxsize,Tcap,0);
         if na>0,a=[1 t(1:na).'];else a=1;end
         b=[zeros(1,nk) t(na+1:na+nb).'];
         v=filter(a,1,z(:,1))-filter(b,1,z(:,2));v(1:ni)=zeros(ni,1);
      end
%
%  *** Determine the initial C-estimate by first building a
%      high order AR-model of the residuals v and the use the 
%      LS-method with the new residuals as inputs ***
%          
        ord=min(na+nb+4*nc,length(v)/3);
  t1=arx(v,ord,maxsize,Tcap,0);
        e=pefilt([1 t1.'],1,v);
        t2=arx([v e],[nd nc 1],maxsize,Tcap,0);
%
%         ** test the stability of the C-estimate **
%
        c=[1 t2(nd+1:nd+nc).']; c=fstab(c);
        t2(nd+1:nd+nc)=c(2:nc+1).';

     if nu==1, t=[t;t2]; else t=t2;end
%
     if nd==0, d=1; else d=[1 t2(1:nd).'];end
     e=pefilt(d,c,v,zeros(1,ni));
  end
end
% *** Display initial estimate ***
%
V=e'*e/(Ncap-ni);
clc, disp(['  INITIAL ESTIMATE'])
disp(['Current loss:' num2str(V)])
disp(['th-vector'])
disp(t)
%
% *** start minimizing ***
%
% ** determine limit for robustification **
 if lim~=0, lim=median(abs(e-median(e)))*lim/0.7;end
 if lim==0,el=e;else
 [ne,me]=size(e);
 ll=ones(ne,me)*lim;la=abs(e)+eps*ll;el=e.*(min(la,ll)./la); clear ll,clear la,end
 g=ones(n,1); l=0; st=0; nmax=max([na nb+nk-1 nc]);
%
% ** the minimization loop **
%
while [norm(g)>tol l<maxiter st~=1]
      l=l+1;
%     * compute gradient *
      yf=filter(-1,c,z(:,1)); ef=filter(1,c,e);
      if nu==1, uf=filter(1,c,z(:,2));end
  M=floor(maxsize/n);
  R=zeros(n);F=zeros(n,1);
  for k1=nmax:M:Ncap-1
      jj=(k1+1:min(Ncap,k1+M));
      psi=zeros(length(jj),n);
      for k=1:na, psi(:,k)=yf(jj-k);end
      for k=1:nb, psi(:,na+k)=uf(jj-k-nk+1);end
      for k=1:nc, psi(:,k+nb+na)=ef(jj-k);end
      R=R+psi'*psi; F=F+psi'*el(jj);
  end
   if Ncap>M, g=R\F; else g=psi\el(jj);end,grad=F;
%
%     * search along the g-direction *
%
      [t1,e,el,V1,c,st]=searchax(z,t,g,lim,V,na,nb,nc,nk,ni);
if st==1,      [t1,e,el,V1,c,st]=searchax(z,t,grad/trace(R)*length(R),lim,V,na,nb,nc,nk,ni);end
      home
      disp(['      ITERATION # ' int2str(l)])
      disp(['Current loss: ' num2str(V1) '  Previous loss: ' num2str(V)])
      disp(['Current th  prev. th   gn-dir'])
      disp([t1 t g])
      disp(['Norm of gn-vector: '  num2str(norm(g))])

      if st==1, disp(['No improvement of the criterion possible along the search direction'])
     disp(['Iterations therefore terminated']),end
      t=t1; V=V1;
end
th=zeros(3+n,max([6+3*nu 7 n]));
V=e'*e/(length(e)-ni);
if nu==1
   th(1,1:9)=[V Tcap 1 na nb nc 0 0 nk];
   else th(1,1:6)=[V Tcap 0 na nc 0];end
th(2,1)=V*(1+n/Ncap)/(1-n/Ncap);
ti=fix(clock); ti(1)=ti(1)/100;
th(2,2:6)=ti(1:5);
th(2,7)=7;
th(3,1:n)=t.';
if maxiter==0,return,end
if Ncap>M, PP=inv(R); else PP=inv(psi'*psi);end
th(4:3+n,1:n)=V*PP;

[Lukas]

I find in folder toolbox other file armax.m but is error Undefined function 'validatePEMInputs' for input arguments of type 'char'. I think that code must be modified for my project or file armax.m is ready for use?

Answer 1

[Image Analyst]

na is defined inside several if statements. If it says it's not defined, then it's not being assigned before you try to use it. So it's not stepping into one of the "if" blocks for some reason. You will discover the reason after you look at this link.