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  1. 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.
  2. 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. In addition, help files are available for all functions, using e.g. ?apollo_mnl
  3. Before asking a question on the forum, users are kindly requested to follow these steps:
    1. Check that the same issue has not already been addressed in the forum - there is a search tool.
    2. 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
    3. Check the frequently asked questions section on the Apollo website, which discusses some common issues/failures. Please see http://www.apollochoicemodelling.com/faq.html
    4. Make sure that R is using the latest official release of Apollo.
  4. If the above steps do not resolve the issue, then users should follow these steps when posting a question:
    1. provide full details on the issue, including the entire code and output, including any error messages
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Search found 3 matches

by nimslkg
16 Jun 2024, 23:35
Forum: Post-estimation analysis/use of results
Topic: Mixed logit model in WTP space - WTP estimates and Delta method
Replies: 1
Views: 24423

Mixed logit model in WTP space - WTP estimates and Delta method

Dear Prof. Hess & Palma,

I estimated a Mixed logit model with normally distributed non-cost attributes and the cost with a negative log-normal distribution in WTP space. I first estimated an MNL model in preference space and used MNL parameters as starting values for the mixed logit model.

Here is ...
by nimslkg
01 Jun 2024, 22:41
Forum: Errors during model validation and/or estimation.
Topic: Error in the model command when using EM algorithms
Replies: 3
Views: 14828

Re: Error in the model command when using EM algorithms

Dear Prof. Hess,

Thank you for your reply.

I downloaded the development version (0.3.3) and ran the apollo_mixEM example first. It ran without any errors or warnings. But when I ran my code, the model did converge; however, I am getting a warning as follows:

WARNING: Singular Hessian, cannot ...
by nimslkg
25 May 2024, 23:56
Forum: Errors during model validation and/or estimation.
Topic: Error in the model command when using EM algorithms
Replies: 3
Views: 14828

Error in the model command when using EM algorithms

Dear Prof. Hess & Palma,

I am trying to estimate a Mixed Multinomial Logit model in WTP space using EM algorithms because I want all the parameters to be random. The model has 11 parameters. 10 parameters are normally distributed and the cost attribute has a negative log-normal distribution. I used ...