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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.
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    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
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  4. If the above steps do not resolve the issue, then users should follow these steps when posting a question:
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Search found 8 matches

by johnathan
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!
by johnathan
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!
by johnathan
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.
by johnathan
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 ...
by johnathan
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 ...
by johnathan
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.
by johnathan
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.
by johnathan
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 ...