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 45 matches
- 23 Apr 2024, 20:21
- Forum: Model specification
- Topic: Accounting for stochastic variables in discrete choice models
- Replies: 1
- Views: 758
Accounting for stochastic variables in discrete choice models
Dear Stephane, I was wondering if it could be necessary to use stochastic variables instead of deterministic variables for the attributes in my Mixed Logit model. I did not find pretty much literature on this topic besides "Diaz et al, 2015, Accounting for stochastic variables in discrete choic...
- 12 Dec 2023, 10:31
- Forum: Post-estimation analysis/use of results
- Topic: Package for export of results into tables
- Replies: 1
- Views: 1130
Package for export of results into tables
Hi Stephane,
is there any recommended package in R that can be used to export the results of the ML models into tables for direct usage in papers?
I´ve tried stargazer, but maybe there is a more comfortable package that can be used?
Any hints are highly recommended.
Thanks and best,
J.
is there any recommended package in R that can be used to export the results of the ML models into tables for direct usage in papers?
I´ve tried stargazer, but maybe there is a more comfortable package that can be used?
Any hints are highly recommended.
Thanks and best,
J.
- 06 Nov 2023, 09:52
- Forum: Model specification
- Topic: Code for Latent class model with covariates
- Replies: 1
- Views: 8410
Code for Latent class model with covariates
Dear Stephane, I´ve tried to write a code for a latent class model with covariates. When defining the utility I used the following coding: V[["class_a"]] = delta_a + gamma_EinstFin_7_a*EinstFin_7 + gamma_FinLue_Angehoerigeetc_a*FinLue V[["class_b"]] = delta_b + gamma_EinstFin_7_b...
- 20 Oct 2023, 13:34
- Forum: Post-estimation analysis/use of results
- Topic: WTP for mixed logit with random parameters
- Replies: 24
- Views: 36113
Re: WTP for mixed logit with random parameters
Dear Stephane, please find below the final model with a normally distributed numerator (with mean mu_HoeheEEE and standard deviation sd_HoeheEEE) and a fixed denominator for price (b_Beitr). I would like to compute the results for the WTP for the HoeheEEE attribute: I would do the following: I would...
- 27 Jul 2023, 17:43
- Forum: Post-estimation analysis/use of results
- Topic: WTP for mixed logit with random parameters
- Replies: 24
- Views: 36113
Re: WTP for mixed logit with random parameters
I am not sure if there is a misunderstanding on my side: 1. So, if my price coefficient b_price is fixed and A2 coefficient is normally or lognormally distributed random I would only use approach 1 to calaculte the WTP for A2? And to get the parameter uncertainty of the standard deviation I will use...
- 24 Jul 2023, 13:03
- Forum: Post-estimation analysis/use of results
- Topic: WTP for mixed logit with random parameters
- Replies: 24
- Views: 36113
Re: WTP for mixed logit with random parameters
Thank you very much for your response. So, if I have fixed price parameter and normally distributed A2 and A3: 1. the delta method calculation below gives me the mean of the WTP and its se (relating to parameter uncertainty): deltaMethod_settings=list(expression=c(WTP_A2="(mu_A2/b_price)",...
- 05 Jul 2023, 18:21
- Forum: Post-estimation analysis/use of results
- Topic: WTP for mixed logit with random parameters
- Replies: 24
- Views: 36113
Re: WTP for mixed logit with random parameters
Yes, the calculations give different information.
So it does not matter what distribution is assumed for A2 and A3 - as long as the price parameter is fixed I can use both calculations as they give different insights into my data?
So it does not matter what distribution is assumed for A2 and A3 - as long as the price parameter is fixed I can use both calculations as they give different insights into my data?
- 05 Jul 2023, 18:01
- Forum: Post-estimation analysis/use of results
- Topic: WTP for mixed logit with random parameters
- Replies: 24
- Views: 36113
Re: WTP for mixed logit with random parameters
Hi Stephane, thank you for your quick reply. So if I assume A2 and A3 being normally distributed I can use the below code to calculate the WTP and its. s.e.: deltaMethod_settings=list(expression=c(WTP_A2="(mu_A2/b_price)", WTP_A3="(mu_A3/b_price)")) apollo_deltaMethod(model, delt...
- 02 Jul 2023, 14:31
- Forum: Post-estimation analysis/use of results
- Topic: Out of sample tests
- Replies: 7
- Views: 8811
Re: Out of sample tests
Hi Stephane, thank you very much for this important clarification! So just to get you right, checking my model fit via Rho² and AIC/BIC as well as LR tests against other model specifications would be a poroper and sufficient way to report the "qualities" of my models? And does the testing ...
- 02 Jul 2023, 13:55
- Forum: Post-estimation analysis/use of results
- Topic: WTP for mixed logit with random parameters
- Replies: 24
- Views: 36113
Re: WTP for mixed logit with random parameters
Hi Stephane, thank you for your reply. 1. So, in order to choose the right type of distribution should I try for different distributions in the code and take a look at the outputs or can also the visualization of conditionals with a code like this be helpful to get an indication which distribution i...