Search found 184 matches: singular covariance

Searched query: singular covariance

by EViews Glenn
Tue Aug 12, 2025 12:20 pm
Forum: General Information and Tips and Tricks
Topic: Mathematical representation of a particular state space model
Replies: 1
Views: 19213

Re: Mathematical representation of a particular state space model

... That said, your interpretation of the H matrix is correct, H will be singular = 192*exp(c(1)) times a 2 x 2 matrix of 1s. As to the state error covariance, I am not sure why you say that it is 2 x 2. Perhaps you left off an equation, but ...
by rrremedio
Wed Aug 06, 2025 6:27 pm
Forum: General Information and Tips and Tricks
Topic: Mathematical representation of a particular state space model
Replies: 1
Views: 19213

Mathematical representation of a particular state space model

... II on State Space Models, my interpretation is as follows: Signal Error Covariance (2x2, H matrix): Since the same named error E1 is used in both signal equations, the resulting H matrix is singular, with all of its elements being equal to 192*EXP(C(1)). Is this correct? ...
by sundar749
Tue Apr 16, 2024 2:31 pm
Forum: Estimation
Topic: Maximum likelihhod estimator sspace showing the result of Probability, z statistic, and standard error as NA
Replies: 1
Views: 29343

Maximum likelihhod estimator sspace showing the result of Probability, z statistic, and standard error as NA

... observations: 46 Convergence achieved after 29 iterations Coefficient covariance computed using outer product of gradients WARNING: Singular covariance - coefficients are not unique Coefficient Std. Error z-Statistic Prob. ...
by MrC
Mon Feb 06, 2023 2:52 am
Forum: Estimation
Topic: Overconstrained model - Constraints too restrictive leading to Singular Covariance error
Replies: 6
Views: 14275

Re: Overconstrained model - Constraints too restrictive leading to Singular Covariance error

Thanks Startz, that's really helpful! I'll have a go away and look into what I can replace it with, if anything!
by startz
Fri Feb 03, 2023 11:45 am
Forum: Estimation
Topic: Overconstrained model - Constraints too restrictive leading to Singular Covariance error
Replies: 6
Views: 14275

Re: Overconstrained model - Constraints too restrictive leading to Singular Covariance error

The model looks a bit like the following: DLOG(Y) = C(1) + C(2)*(LOG(Yt-1) + C(3)*LOG(Xt-1) + (1-C(3))*LOG(Zt-1)) + C(4)*DLOG(Xt-1) + C(5)*DLOG(Zt-1) + (1-C(4)-C(5))*DLOG(Ut) Where I'd want constraints such as: -1 < C(2) and C(3) < 0 C(4) and C(5) >0 I @LOGIT some of the coefficients to get round t...
by MrC
Fri Feb 03, 2023 10:07 am
Forum: Estimation
Topic: Overconstrained model - Constraints too restrictive leading to Singular Covariance error
Replies: 6
Views: 14275

Re: Overconstrained model - Constraints too restrictive leading to Singular Covariance error

In the generic model you posted, the only thing that's nonlinear is c(3). If your real model is different from that then it's hard to say much without seeing the real model. The model looks a bit like the following: DLOG(Y) = C(1) + C(2)*(LOG(Yt-1) + C(3)*LOG(Xt-1) + (1-C(3))*LOG(Zt-1)) + C(4)*DLOG...
by startz
Fri Feb 03, 2023 7:07 am
Forum: Estimation
Topic: Overconstrained model - Constraints too restrictive leading to Singular Covariance error
Replies: 6
Views: 14275

Re: Overconstrained model - Constraints too restrictive leading to Singular Covariance error

In the generic model you posted, the only thing that's nonlinear is c(3). If your real model is different from that then it's hard to say much without seeing the real model.
by MrC
Fri Feb 03, 2023 3:15 am
Forum: Estimation
Topic: Overconstrained model - Constraints too restrictive leading to Singular Covariance error
Replies: 6
Views: 14275

Re: Overconstrained model - Constraints too restrictive leading to Singular Covariance error

What do you get for point estimates? I'll get values of something like -0.5 for a coefficient that should be 0.5. Also all the variables are logged! It's also built into an error correction framework, so sometimes the long-run variable will have the right sign while the short-run differenced one wi...
by MrC
Thu Feb 02, 2023 9:38 am
Forum: Estimation
Topic: Overconstrained model - Constraints too restrictive leading to Singular Covariance error
Replies: 6
Views: 14275

Overconstrained model - Constraints too restrictive leading to Singular Covariance error

... starting values for the parameters I will get the error: "WARNING: Singular covariance - coefficients are not unique" with NA's in place of the std. errors, t-stats, ...
by EViews Glenn
Wed Nov 30, 2022 3:54 pm
Forum: Programming
Topic: singular covariance in Kalman filtering
Replies: 1
Views: 3696

Re: singular covariance in Kalman filtering

It is the covariance of the coefficients. It is a little difficult to diagnose without looking at ... I think you are right about overidentification. I will note that in the second (non-singular) parameterization, you are only estimating a single share coefficient instead of ...
by remuct
Wed Nov 30, 2022 3:04 pm
Forum: Programming
Topic: singular covariance in Kalman filtering
Replies: 1
Views: 3696

singular covariance in Kalman filtering

Hi, I have a concern about a "singular covariance" message which came with the output of a Kalman filter estimation. I am wondering which ...
by ndzama
Fri Sep 02, 2022 4:42 am
Forum: Programming
Topic: WARNING: Singular covariance - coefficients are not unique
Replies: 0
Views: 14050

WARNING: Singular covariance - coefficients are not unique

... State Space equations, but I encounter this message "WARNING: Singular covariance - coefficients are not unique" on state space output. I have been trying to ...
by tinfah
Tue May 17, 2022 3:30 am
Forum: Estimation
Topic: logistic using binary variable
Replies: 3
Views: 5422

Re: logistic using binary variable

... 1 1004 Included observations: 919 Failure to improve likelihood (singular hessian) after 6 iterations Coefficient covariance computed using observed Hessian WARNING: Singular covariance - coefficients are ...

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