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. This may take a day or two at busy times. There is no need to submit the post multiple times.

Search found 1038 matches

by stephanehess
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: 7
Views: 107

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) ...
by stephanehess
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: 7
Views: 107

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
by stephanehess
07 May 2024, 07:52
Forum: Estimation results
Topic: Positive price coefficient in RPL model estimation
Replies: 5
Views: 71

Re: Positive price coefficient in RPL model estimation

you can do, if you really think a Normal makes sense (it normally does not)
by stephanehess
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: 50

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
by stephanehess
06 May 2024, 08:26
Forum: Model specification
Topic: Two level Nested Logit(NL) model specification for many alternatives
Replies: 1
Views: 30

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
by stephanehess
06 May 2024, 08:22
Forum: Model specification
Topic: Start values for wta parameter
Replies: 3
Views: 2490

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
by stephanehess
06 May 2024, 08:19
Forum: Model specification
Topic: ICLV model specification in unlabelled form
Replies: 8
Views: 7509

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 ...
by stephanehess
06 May 2024, 08:13
Forum: Model specification
Topic: adding context variables in class allocation model in latent class logit model
Replies: 4
Views: 1646

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
by stephanehess
06 May 2024, 08:08
Forum: Post-estimation analysis/use of results
Topic: Elasticity analysis for unlabeled alternatives
Replies: 1
Views: 17

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...
by stephanehess
06 May 2024, 08:03
Forum: Post-estimation analysis/use of results
Topic: Out of sample results
Replies: 3
Views: 1728

Re: Out of sample results

Hi apologies for the slow reply So what you're finding is that you MMNL overfits the estimation data a bit more than MNL, but these differences are small. No, Apollo does not compute the % correct predicted metric as this is a misleading metric that is contrary to probabilistic choice models. It sho...