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. In addition, help files are available for all functions, using e.g. ?apollo_mnl
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- 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.
- Users can check which version they are running by entering packageVersion("apollo").
- Then check what is the latest full release (not development version) at http://www.ApolloChoiceModelling.com/code.html.
- To update to the latest official version, just enter install.packages("apollo"). To update to a development version, download the appropriate binary file from http://www.ApolloChoiceModelling.com/code.html, and install the package from file
- 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
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Search found 8 matches
- 07 Oct 2025, 18:52
- Forum: Feature requests
- Topic: Return RAM in apollo_speedTest
- Replies: 2
- Views: 1036
Re: Return RAM in apollo_speedTest
Great to hear, thanks!
- 03 Oct 2025, 22:53
- Forum: Feature requests
- Topic: Return RAM in apollo_speedTest
- Replies: 2
- Views: 1036
Return RAM in apollo_speedTest
The RAM is reported in the console, but not returned. It would be useful to save via the function outputs. Thanks!
- 02 Oct 2025, 21:36
- Forum: Feature requests
- Topic: Parallel Processing for apollo_searchStart
- Replies: 4
- Views: 4585
Re: Parallel Processing for apollo_searchStart
Ok, thank you for the insight and consideration. I will try to email it after sorting out a few things.
- 02 Oct 2025, 21:32
- Forum: Bug reports
- Topic: apollo_searchStart Test2 Conditions?
- Replies: 1
- Views: 722
apollo_searchStart Test2 Conditions?
I am not sure if test2 is applying its conditions properly in apollo_searchStart. This is it's description from the beginning of the code:
Tolerance for test 2. A candidate is discarded if the norm of its gradient is smaller than \code{gTest} AND its LL is further than \code{llTest} from a better ...
Tolerance for test 2. A candidate is discarded if the norm of its gradient is smaller than \code{gTest} AND its LL is further than \code{llTest} from a better ...
- 12 Sep 2025, 16:32
- Forum: Feature requests
- Topic: Parallel Processing for apollo_searchStart
- Replies: 4
- Views: 4585
Re: Parallel Processing for apollo_searchStart
I have attempted this, in addition to some other modifications for the searchStart function for my project. One other change was to track why solutions were pruned & how many ended up converging to the global/best solution. I also performed my sampling for the LCL/MXL based on the MNL solution ...
- 28 Aug 2025, 21:09
- Forum: Feature requests
- Topic: Parallel Processing for apollo_searchStart
- Replies: 4
- Views: 4585
Parallel Processing for apollo_searchStart
Being able to parallelize the search start execution would drastically increase computational time when evaluating a large number of starting points.
- 10 Apr 2025, 18:52
- Forum: Model specification
- Topic: ANA_EM has no covariance matrix
- Replies: 15
- Views: 113298
Re: ANA_EM has no covariance matrix
Hi David,
Thank you for your response. I commented that line out during troubleshooting, but uncommenting it does not change the error.
I plan to reach out via email after organizing my work. Thanks again for your help.
Thank you for your response. I commented that line out during troubleshooting, but uncommenting it does not change the error.
I plan to reach out via email after organizing my work. Thanks again for your help.
- 17 Mar 2025, 20:43
- Forum: Model specification
- Topic: ANA_EM has no covariance matrix
- Replies: 15
- Views: 113298
Re: ANA_EM has no covariance matrix
Hi
you need to put Q into apollo_inputs after the line
apollo_inputs = apollo_validateInputs()
using
apollo_inputs$Q = Q
and then everywhere else in apollo_lcPars and apollo_probabilities, you need to replace Q by apollo_inputs$Q
Stephane
Hi Stephane,
This recommendation addressed an ...