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. This may take a day or two at busy times. There is no need to submit the post multiple times.
Search found 1039 matches
- 07 May 2024, 15:57
- Forum: Errors during model validation and/or estimation.
- Topic: Error in estimating Latent class model with RP-SP data
- Replies: 9
- Views: 148
Re: Error in estimating Latent class model with RP-SP data
yes, having all the starting values at zero also led to an issue with the initial check of the gradients. It's always good practice to use different starting values in different classes
- 07 May 2024, 10:24
- Forum: Errors during model validation and/or estimation.
- Topic: Error in estimating Latent class model with RP-SP data
- Replies: 9
- Views: 148
Re: Error in estimating Latent class model with RP-SP data
Hi two changes are needed in your code. As apollo_combineModels is called inside the latent class model, you need P[[paste0("Class_",s)]] = apollo_combineModels(P_temp, apollo_inputs, functionality,components=c(paste0("RP_class_",s),paste0("SP_class_",s)),asList=FALSE) ...
- 07 May 2024, 07:55
- Forum: Errors during model validation and/or estimation.
- Topic: Error in estimating Latent class model with RP-SP data
- Replies: 9
- Views: 148
Re: Error in estimating Latent class model with RP-SP data
Can you share your code and data with me outside the forum, and I'll try to debug it for you
- 07 May 2024, 07:52
- Forum: Estimation results
- Topic: Positive price coefficient in RPL model estimation
- Replies: 5
- Views: 95
Re: Positive price coefficient in RPL model estimation
you can do, if you really think a Normal makes sense (it normally does not)
- 06 May 2024, 13:09
- Forum: Model estimation
- Topic: Need Advice on Using CFA Model Results from other software with ICLV in Apollo
- Replies: 3
- Views: 62
Re: Need Advice on Using CFA Model Results from other software with ICLV in Apollo
Hi
yes, I understood you were doing the factor analysis in another package. But you would never use factor scores in an ICLV model. What would do is check what groupings the factor analysis gives you and implement the ICLV model accordingly
Stephane
yes, I understood you were doing the factor analysis in another package. But you would never use factor scores in an ICLV model. What would do is check what groupings the factor analysis gives you and implement the ICLV model accordingly
Stephane
- 06 May 2024, 08:26
- Forum: Model specification
- Topic: Two level Nested Logit(NL) model specification for many alternatives
- Replies: 1
- Views: 38
Re: Two level Nested Logit(NL) model specification for many alternatives
Hi
apologies for the slow reply, your message had got lost
Did you try with lambda=1 as a starting value. Essentially, you should first see if you can replicate MNL
Stephane
apologies for the slow reply, your message had got lost
Did you try with lambda=1 as a starting value. Essentially, you should first see if you can replicate MNL
Stephane
- 06 May 2024, 08:22
- Forum: Model specification
- Topic: Start values for wta parameter
- Replies: 3
- Views: 2519
Re: Start values for wta parameter
Anat
apologies for the very slow reply.
I would use a lognormal distribution indeed. It's not about whether you have an opt-out or not, really, but about whether it would make sense behaviourally for people to have a diferently signed coefficient
Stephane
apologies for the very slow reply.
I would use a lognormal distribution indeed. It's not about whether you have an opt-out or not, really, but about whether it would make sense behaviourally for people to have a diferently signed coefficient
Stephane
- 06 May 2024, 08:19
- Forum: Model specification
- Topic: ICLV model specification in unlabelled form
- Replies: 8
- Views: 7532
Re: ICLV model specification in unlabelled form
Hi many apologies for the slow reply, your messages had been lost. First, "relative function convergence" is the BGW terminology for convergence, so that's fine. Second, in relation to your ASCs, you have: b_ASC*(asc_alt1==0) + b_ASC*(asc_alt1==1) which would mean the ASC is used for both ...
- 06 May 2024, 08:13
- Forum: Model specification
- Topic: adding context variables in class allocation model in latent class logit model
- Replies: 4
- Views: 1668
Re: adding context variables in class allocation model in latent class logit model
Hi
apologies for the slow reply
Your problem is caused by the effects coding you have implemented in the data. If you have only three levels, then you should also only estimated two parameters, not three. But I would suggest you just use dummy coding
Stephane
apologies for the slow reply
Your problem is caused by the effects coding you have implemented in the data. If you have only three levels, then you should also only estimated two parameters, not three. But I would suggest you just use dummy coding
Stephane
- 06 May 2024, 08:08
- Forum: Post-estimation analysis/use of results
- Topic: Elasticity analysis for unlabeled alternatives
- Replies: 1
- Views: 30
Re: Elasticity analysis for unlabeled alternatives
Hi many apologies for the slow reply, we had missed your post In relation to your questions: 1. Is classical elasticity analysis suitable for unlabeled cases? (While computations may be possible, I am interested in ascertaining the theoretical relevance of confirming sensitivity to specific attribut...