Hi
apologies for the slow reply. Could you share your code and data with me outside the forum and I'll have a look for you
Stephane
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
- 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.
- 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
- posts will not immediately appear on the forum, but will be checked by a moderator first. We check the forum at least twice a week. It may thus take a couple of days for your post to appear and before we reply. There is no need to submit the post multiple times.
Search found 1338 matches
- 29 Nov 2025, 13:41
- Forum: Installation and updating
- Topic: Error in value[[3L]](cond) : unused argument (cond) in in Hybrid MMNL Model
- Replies: 1
- Views: 98
- 29 Nov 2025, 13:38
- Forum: Model specification
- Topic: Doubts about model specification with an alternative vs. status quo
- Replies: 5
- Views: 753
Re: Doubts about model specification with an alternative vs. status quo
hi
what I mean is that you could estimate a parameter for each level, and then plot their estimates against the values and see if it looks linear
Stephane
what I mean is that you could estimate a parameter for each level, and then plot their estimates against the values and see if it looks linear
Stephane
- 29 Nov 2025, 13:36
- Forum: Model estimation
- Topic: Latent Class Choice Model: NaNs produced
- Replies: 1
- Views: 147
Re: Latent Class Choice Model: NaNs produced
Hi
in general, using LVs in the class allocation model is empirically difficult and often leads to issues.
In your case, I would look at those parameters for which you do not obtain classical standard errors
Stephane
in general, using LVs in the class allocation model is empirically difficult and often leads to issues.
In your case, I would look at those parameters for which you do not obtain classical standard errors
Stephane
- 29 Nov 2025, 13:33
- Forum: Model specification
- Topic: weighted choice model
- Replies: 1
- Views: 121
Re: weighted choice model
Hi
no, it cannot. The weights need to be provided by the user as values
Stephane
no, it cannot. The weights need to be provided by the user as values
Stephane
- 29 Nov 2025, 13:32
- Forum: Model specification
- Topic: Parameter does not influence the log-likelihood of your model!
- Replies: 12
- Views: 25274
Re: Parameter does not influence the log-likelihood of your model!
Hi
in your case, it's likely the line breaks. See the point at https://apollochoicemodelling.com/faq.html
Search for Why do I get an error saying that one of my parameters does not influence the likelihood, even though I am using it in a utility function?
Stephane
in your case, it's likely the line breaks. See the point at https://apollochoicemodelling.com/faq.html
Search for Why do I get an error saying that one of my parameters does not influence the likelihood, even though I am using it in a utility function?
Stephane
- 29 Nov 2025, 13:30
- Forum: Estimation results
- Topic: Interpretation of MXL Standard Errors using weighting
- Replies: 3
- Views: 426
Re: Interpretation of MXL Standard Errors using weighting
That's simply ensuring that the weights sum to N, but the same issues remain. It's much better to just incorporate interactions, and then reweight your results
- 29 Nov 2025, 13:27
- Forum: Model specification
- Topic: Unlabelled BNL can not estimate the s.e or t-ratio
- Replies: 1
- Views: 108
Re: Unlabelled BNL can not estimate the s.e or t-ratio
Hi
difficult to know without looking at the data. can you share the data and code with me outside the forum and I'll have a look
Stephane
difficult to know without looking at the data. can you share the data and code with me outside the forum and I'll have a look
Stephane
- 29 Nov 2025, 13:25
- Forum: Errors during model validation and/or estimation.
- Topic: Individual weights error with LC model
- Replies: 1
- Views: 139
Re: Individual weights error with LC model
Hi
yes, you're doing it at the wrong place, I believe. I woiuld do the weigthing after the call to apollo_lc
Also, you really should not use Halton draws with so many random terms, and you need many more draws too
Hope this helps
Stephane
yes, you're doing it at the wrong place, I believe. I woiuld do the weigthing after the call to apollo_lc
Also, you really should not use Halton draws with so many random terms, and you need many more draws too
Hope this helps
Stephane
- 23 Oct 2025, 17:15
- Forum: Bug reports
- Topic: apollo_searchStart Test2 Conditions?
- Replies: 1
- Views: 324
Re: apollo_searchStart Test2 Conditions?
Hi
thanks for spotting this. This will be fixed in version 0.3.7
We may make a development version online in the next few days on the apollo website, prior to the CRAN release later this year
Best wishes
David & Stephane
thanks for spotting this. This will be fixed in version 0.3.7
We may make a development version online in the next few days on the apollo website, prior to the CRAN release later this year
Best wishes
David & Stephane
- 23 Oct 2025, 14:39
- Forum: Errors during model validation and/or estimation.
- Topic: Latent Class - BHHH matrix singular
- Replies: 3
- Views: 718
Re: Latent Class - BHHH matrix singular
Hi
easy one to fix.
Your model is overspecified. You have two classes, so you cannot estimate the parameters for both classes in the class allocation model. You need to fix delta_a or delta_b
Stephane
easy one to fix.
Your model is overspecified. You have two classes, so you cannot estimate the parameters for both classes in the class allocation model. You need to fix delta_a or delta_b
Stephane