Important: Read this before posting to this forum

  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
    2. 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 13 matches

by kiki
05 Nov 2025, 18:14
Forum: Model specification
Topic: weighted choice model
Replies: 1
Views: 31897

weighted choice model

Hi,

I am currently working on a weighted choice model, and I am wondering whether the weight function can be defined in terms of parameters, and if so, whether these parameters can be estimated as part of the overall model.

Thank you!
by kiki
08 Oct 2025, 20:13
Forum: Examples (existing and requests for new ones)
Topic: Nested Latent Class Model
Replies: 5
Views: 46749

Re: Nested Latent Class Model

Hi Stephane,

I have attached the code I tried to implement for a two-layer latent class model. In the code, “k” corresponds to the inner classes (following the IANA structure) and “s” corresponds to the outer classes (following the conventional latent class structure).

When I run the code, I ...
by kiki
13 Aug 2025, 14:53
Forum: Examples (existing and requests for new ones)
Topic: Nested Latent Class Model
Replies: 5
Views: 46749

Re: Nested Latent Class Model

Hi Stephone,

Thank you! The mathematical example can be referred in the paper named "A model for the simultaneous inference of attribute nonattendance and taste heterogeneity", Eq(1)-(9).

The outer latent classes are specified as a conventional latent class model, where each class has its own set ...
by kiki
03 Aug 2025, 22:31
Forum: Examples (existing and requests for new ones)
Topic: Nested Latent Class Model
Replies: 5
Views: 46749

Nested Latent Class Model

Hi,

I am currently working with latent class models in Apollo and would like to inquire whether it is possible to implement a hierarchical latent class model. That is, a model structure allows for subclasses nested within higher-level latent classes.

If this is supported, could you kindly provide ...
by kiki
07 May 2025, 14:02
Forum: Post-estimation analysis/use of results
Topic: Cross validation and Prediction
Replies: 1
Views: 21138

Cross validation and Prediction

Hi,

I am working on comparing the prediction performance of mixed logit models estimated with and without weighting calibration using the Apollo package. The weights have been applied at the task level (i.e., per row in the dataset).

I try to compare their prediction performance indicators such as ...
by kiki
31 Oct 2024, 23:37
Forum: Estimation results
Topic: has large Estimates and Std.
Replies: 1
Views: 25265

has large Estimates and Std.

Hi,

I am reaching out to you again! I used effected coding as input variabels. When I use latent class model and also adjust the intial value of variables, it estimates very large estimates and Std as below. I attached my code after the results.

I also try the EM_LC. EM_LC can estimates proper ...
by kiki
04 Sep 2024, 11:11
Forum: Model specification
Topic: ANA_EM has no covariance matrix
Replies: 15
Views: 147020

Re: ANA_EM has no covariance matrix

Hi Stephane,

Thank you! The mathematical explanation about my desired model can be referred to "A discrete choice model with endogenous attribute attendance"
and "It’s not that I don’t care, I just don’t care very much: confounding between attribute non-attendance and taste heterogeneity".

As I ...
by kiki
14 Aug 2024, 12:19
Forum: Model specification
Topic: ANA_EM has no covariance matrix
Replies: 15
Views: 147020

Re: ANA_EM has no covariance matrix

Hi Stephane,

Thank you for your solution. While after fixing this issue, another issue is coming, which is about "Error in apollo_preprocess(inputs = classAlloc_settings, modelType, functionality, :
SYNTAX ISSUE - Each element of "utilities" for model component "classAlloc" needs to be a scalar ...
by kiki
12 Aug 2024, 18:25
Forum: Model specification
Topic: ANA_EM has no covariance matrix
Replies: 15
Views: 147020

Re: ANA_EM has no covariance matrix

HI Stephane,

I re-check my code. I notice i mix-used the code of EM and Gradient descent. After revision, the issue becomes:

"Error in checkForRemoteErrors(lapply(cl, recvResult)) :
3 nodes produced errors; first error: object 'Q' not found" .

I attached the code and results. Thank you in ...
by kiki
25 Jul 2024, 17:20
Forum: Model specification
Topic: ANA_EM has no covariance matrix
Replies: 15
Views: 147020

Re: ANA_EM has no covariance matrix

Hi Stephane,

I adjust my code, but it still does not have the covariance matrix. And I also notice the class probability are always same for the class_1, class_2, and class_3. I also check with relevant topic discussed in forum, but it does not work.

I attached the codes and results as follows ...