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 5 matches
- 13 Jan 2022, 16:28
- Forum: Post-estimation analysis/use of results
- Topic: Delta method in random parameter models
- Replies: 14
- Views: 17766
Re: Delta method in random parameter models
Stephane, The cost attribute is an opportunity cost, time. It was the time in minutes required for each option. Our discrete choice setting does not have a standard monetary cost or price. Sorry if this was not clear in my original post. I see your important point about assuming independence in the ...
- 12 Jan 2022, 23:05
- Forum: Post-estimation analysis/use of results
- Topic: Delta method in random parameter models
- Replies: 14
- Views: 17766
Re: Delta method in random parameter models
Hi David, No, you cannot use apollo_deltaMethod to calculate WTP when you have random coefficients. apollo_deltaMethod works only for fixed (as in non-random parameters). Instead, you have a couple of alternatives to calculate WTP when using random coefficients. Do simulation: That is what you did ...
- 04 Jan 2022, 04:57
- Forum: Errors during model validation and/or estimation.
- Topic: Error estimating a mixed MNL with only one random attribute
- Replies: 2
- Views: 2649
Error estimating a mixed MNL with only one random attribute
Hi, I am estimating a mixed multinomial logistic regression on a stated preference discrete choice experiment with two options and an opt-out option with the latest version of Apollo (0.2.6). I am able to estimate the code without error, until I include intra- draws. When I include intra-individual ...
- 21 Oct 2021, 19:51
- Forum: Model specification
- Topic: Choice sets with large numbers of alternatives
- Replies: 8
- Views: 12299
Re: Choice sets with large numbers of alternatives
Stephane, Yes, Thank you! This is what I thought, but was probably confusing myself by reading about some of the more complex set ups. I'm new to Apollo so thanks for making it easy. - Alice
- 20 Oct 2021, 19:55
- Forum: Model specification
- Topic: Choice sets with large numbers of alternatives
- Replies: 8
- Views: 12299
Re: Choice sets with large numbers of alternatives
Hi, I am having a similar but not identical problem. I also have a discrete choice model with a large number of alternatives, but it is a stated preference discrete choice experiment with an efficient design. In the data, there are 1096 possible alternatives where each choice task has two options (a...