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 7 matches
- 01 Mar 2023, 14:40
- Forum: Estimation results
- Topic: Higher LL(final) than LL(0) for one latent class
- Replies: 3
- Views: 3485
Re: Higher LL(final) than LL(0) for one latent class
That is a huge relief, thank you!
- 01 Mar 2023, 14:39
- Forum: Estimation results
- Topic: Higher LL(final) than LL(0) for one latent class
- Replies: 3
- Views: 3485
Re: Higher LL(final) than LL(0) for one latent class
That is a huge relief, thank you!
- 28 Feb 2023, 19:53
- Forum: Estimation results
- Topic: Higher LL(final) than LL(0) for one latent class
- Replies: 3
- Views: 3485
Higher LL(final) than LL(0) for one latent class
I have been using latent class FMNLs to associate respondent characteristics with their preferences in a discrete choice experiment. I am unsure about the validity of several competing model fits. In these cases, although the LL for the full model is higher than the starting LL, the LL of one or mor...
- 15 Mar 2022, 14:42
- Forum: Model estimation
- Topic: Fitting LC mod to simulated data--NA values for SE
- Replies: 6
- Views: 7077
Re: Fitting LC mod to simulated data--NA values for SE
I think I actually found the problem! I was simulating responses where respondents would allocate 10 'days' to each of the options. So identical choice scenarios were getting a variety of responses from the same respondent, which I think broke the estimation in some way. When I simulate a normal dis...
- 12 Mar 2022, 17:48
- Forum: Model estimation
- Topic: Fitting LC mod to simulated data--NA values for SE
- Replies: 6
- Views: 7077
Re: Fitting LC mod to simulated data--NA values for SE
The sum of the log of choice probabilities is -83830.22 on the troubleshooting version I have just estimated. From the model outputs, the LL0 is -120707.8. If I'm doing this right, I think that gives me an rho2 of 0.31? I'm not sure how to interpret this in this context, I'm sorry.
- 10 Mar 2022, 15:49
- Forum: Model estimation
- Topic: Fitting LC mod to simulated data--NA values for SE
- Replies: 6
- Views: 7077
Re: Fitting LC mod to simulated data--NA values for SE
Thanks for your reply! I simulated the data by calculating the probability of an individual choosing each alternative in a scenario (P(choice) = exp(Bx)/sum(exp(Bx)) and then sampling the choice from the alternatives at those probabilities. I'm traveling now and can't immediately show the code, but ...
- 09 Mar 2022, 22:50
- Forum: Model estimation
- Topic: Fitting LC mod to simulated data--NA values for SE
- Replies: 6
- Views: 7077
Fitting LC mod to simulated data--NA values for SE
I am trying to code a power analysis for a discrete choice experiment that I am planning. I have generated fake data simulating the choices of three latent classes of respondents. Each class has its own known beta values and a MNL predicting their choices from three alternatives and two opt-out opti...