@signal cy = c(1) + sv1*zhc + [var = exp(c(2))]
@state sv1 =c(3)+c(4)* sv1(-1)+[var = exp(c(5))]
Sspace: ESSAY   
Method: Maximum likelihood (Marquardt)   
Date: 06/15/09   Time: 13:24   
Sample: 1995 2007   
Included observations: 13   
Convergence achieved after 1 iteration   
WARNING: Singular covariance - coefficients are not unique   
   
Coefficient Std. Error z-Statistic Prob.  
   
C(1) -2789.831 NA NA NA
C(2) 18.10923 NA NA NA
C(3) 4.231287 NA NA NA
C(4) 0.782116 NA NA NA
C(5) -334.7372 NA NA NA
   
Final State Root MSE z-Statistic Prob.  
各位高手帮我看下哪里出问题了，怎么都是na?