Important: Read this before posting to this forum
- This forum is for questions related to the use of Apollo. We will answer some general choice modelling questions too, where appropriate, and time permitting. We cannot answer questions about how to estimate choice models with other software packages.
- There is a very detailed manual for Apollo available at http://www.ApolloChoiceModelling.com/manual.html. This contains detailed descriptions of the various Apollo functions, and numerous examples are available at http://www.ApolloChoiceModelling.com/examples.html.
- Before asking a question on the forum, users are kindly requested to follow these steps:
- Check that the same issue has not already been addressed in the forum - there is a search tool.
- Ensure that the correct syntax has been used. For any function, detailed instructions are available directly in Apollo, e.g. by using ?apollo_mnl for apollo_mnl
- Check the frequently asked questions section on the Apollo website, which discusses some common issues/failures. Please see http://www.apollochoicemodelling.com/faq.html
- Make sure that R is using the latest official release of Apollo.
- If the above steps do not resolve the issue, then users should follow these steps when posting a question:
- provide full details on the issue, including the entire code and output, including any error messages
- posts will not immediately appear on the forum, but will be checked by a moderator first. This may take a day or two at busy times. There is no need to submit the post multiple times.
Ask questions about the results reported after estimation. If the output includes errors, please include your model code if possible.
- Posts: 6
- Joined: 08 Sep 2021, 16:52
I have tried several specifications of Hybrid Choice Model with Bayesian Estimator to solve my choice problem. My data contains several mode specific LVs in addition to other observable attributes like trip characteristics. I used initial 100k iterations as burn-in and next 100k for estimation. But after completing the estimation, I come across the same error each time:
Code: Select all
WARNING: RSGHB has censored the probabilities. Please note that in at least some iterations RSGHB has avoided numerical
issues by left censoring the probabilities. This has the side effect of zero or negative probabilities not leading to
1: In log(test2_LL) : NaNs produced
2: In log(test1_LL) : NaNs produced
The problem as I seen in my results is most probably related to estimation of covariance matrix (though not 100% sure).
It shows the initial loglikelihood value to -Inf though it was somewhere around -56000 when I started estimation.
I produces correlation matrices but NaNs in covariance matrices, what is the reason for that? I read somewhere that correlation matrix is unstandardized version of covariance matrix. Can you please suggest on this also?
I am attaching the code as well as my results.
- (28.29 KiB) Downloaded 215 times