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 9 matches

by Andy
22 Feb 2021, 17:00
Forum: Post-estimation analysis/use of results
Topic: Delta method for lognormal parameters
Replies: 4
Views: 6217

Re: Delta method for lognormal parameters

Dear Stephane,

Thank you very much for your prompt and helpful reply.

Kind regards
Andy
by Andy
22 Feb 2021, 14:16
Forum: Post-estimation analysis/use of results
Topic: Delta method for lognormal parameters
Replies: 4
Views: 6217

Re: Delta method for lognormal parameters

Dear Stephane, Thanks a lot. Here they are. I am sorry for the bad format. I did not know how to include tables here. Estimates: Estimate Rob.std.err. Rob.t.ratio(0) mu_log_beta 0.0685 0.1716 0.4 sigma_log_beta_inter 0.5892 0.2025 2.91 Robust covariance matrix: mu_log_beta sigma_log_beta_inter mu_lo...
by Andy
17 Feb 2021, 14:49
Forum: Post-estimation analysis/use of results
Topic: Delta method for lognormal parameters
Replies: 4
Views: 6217

Delta method for lognormal parameters

Dear Stephane Hess, I estimated a mixed logit model with lognormal random parameters. According to the manual, I used the following expression: exp(mu_log_beta + sigma_log_beta_inter * draws_beta_inter) Furthermore, I used the Delta method to calculate the mean and standard deviation of the lognorma...
by Andy
22 Oct 2020, 11:48
Forum: Post-estimation analysis/use of results
Topic: Correlation between random parameters
Replies: 2
Views: 4381

Re: Correlation between random parameters

Dear Stephane,

Thank you very much. This is an elegant solution and helps a lot.

Best regards
Andy
by Andy
21 Oct 2020, 18:36
Forum: Model specification
Topic: Parameter restrictions
Replies: 2
Views: 4390

Re: Parameter restrictions

Dear Stephane,

Thank you very much!

Best regards
Andy
by Andy
21 Oct 2020, 16:50
Forum: Post-estimation analysis/use of results
Topic: Correlation between random parameters
Replies: 2
Views: 4381

Correlation between random parameters

Dear Stephane Hess,

In the manual, it is stated that the correlation of random parameters can be calculated using apollo_unconditionals. I wonder if there is an example that shows the code for calculating the correlations.

Kind regards
Andy
by Andy
21 Oct 2020, 15:07
Forum: Model specification
Topic: Parameter restrictions
Replies: 2
Views: 4390

Parameter restrictions

Dear Stephane Hess,

Is there an easy way to impose restrictions on parameters, such as Beta_time_bus = Beta_time_train, without directly manipulating the utility functions?

Kind regards
Andy
by Andy
26 Aug 2020, 14:55
Forum: Post-estimation analysis/use of results
Topic: Mean and variance of the log-normal WTP considering the complex heterogeneity structure of the coefficient, ex. ch. 6.1
Replies: 2
Views: 4467

Mean and variance of the log-normal WTP considering the complex heterogeneity structure of the coefficient, ex. ch. 6.1

Dear Stephane Hess, Dear David Palma, I want to ask a question to your example incorporating random heterogeneity on p. 68 of the manual. I was wondering how to calculate the mean and the standard deviation of the log-normal WTP for travel time and headway. I guess for headway one can use the usual ...