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 15 matches

by DavidKL
25 Oct 2022, 09:56
Forum: Estimation results
Topic: Positive alternative specific constant for the opt-out
Replies: 1
Views: 3052

Positive alternative specific constant for the opt-out

Hi Apollo team! I had a pilot study with 54 respondents and I got an interesting results. I have 8 decision situations with 3 alternatives and an opt-out option. I got the following results for the choices: Overview of choices for MNL model component : alt1 alt2 alt3 altnc Times available 432.00 432...
by DavidKL
16 Aug 2021, 17:45
Forum: Post-estimation analysis/use of results
Topic: Delta method in random parameter models
Replies: 14
Views: 17347

Re: Delta method in random parameter models

Hi Stephane!

Thank you for the answer and help!

I will try to use the EM algorithm.

Best wishes,
David
by DavidKL
13 Aug 2021, 15:15
Forum: Post-estimation analysis/use of results
Topic: Delta method in random parameter models
Replies: 14
Views: 17347

Re: Delta method in random parameter models

Hi Stephane, thank you for the answer! I get very different solution not only in latent class model with random parameters, but also in latent class with fix parameters. My code and the results are the following in preference space: ### Clear memory rm(list = ls()) ### Load Apollo library library(ap...
by DavidKL
09 Aug 2021, 20:33
Forum: Post-estimation analysis/use of results
Topic: Delta method in random parameter models
Replies: 14
Views: 17347

Re: Delta method in random parameter models

Hi David! I have tried to use several starting values, but neither LC nor RLC model did not converge to the same solution in the WTP space as it was estimated in the preference space (e.g. I got 0.15 - 0.85 class probability values in preference-space, while 0.47-0.53 in WTP-space). I will try to ap...
by DavidKL
09 Aug 2021, 19:13
Forum: Post-estimation analysis/use of results
Topic: Delta method in random parameter models
Replies: 14
Views: 17347

Re: Delta method in random parameter models

Hi David! Thank you very much for your quick and helpful answer! I have estimated a two-class LC model with random parameters (only within class). I tried to use WTP-space approach, but class allocation probabilites were very different as in preference-space. So I assume that, my model in WTP-space ...
by DavidKL
08 Aug 2021, 15:41
Forum: Post-estimation analysis/use of results
Topic: Delta method in random parameter models
Replies: 14
Views: 17347

Delta method in random parameter models

Hi David and Stephane! How could I calculate standard errors for mean WTP-s in case of random parameter models? I use the following formulation to calculate mean WTP-s: unconditionals=apollo_unconditionals(model,apollo_probabilities,apollo_inputs) attribute=unconditionals[["b_attribute"]] ...
by DavidKL
29 Jul 2021, 18:11
Forum: Bug reports
Topic: Error message "duplicated componentName" in Hybrid Choice Model using Bayesian approach
Replies: 4
Views: 14331

Re: Error message "duplicated componentName" in Hybrid Choice Model using Bayesian approach

Hi, I get the same error message. "Error in apollo_normalDensity(Qq2, functionality) : Duplicated componentName found (NormD). Names must be different for each component." My specification is the following: # ################################################################# # #### LOAD LIB...
by DavidKL
13 Jul 2021, 15:21
Forum: Model estimation
Topic: Interaction effect with ASC
Replies: 2
Views: 5514

Re: Interaction effect with ASC

Perfect, thanks for the help!
by DavidKL
13 Jul 2021, 10:43
Forum: Model estimation
Topic: Interaction effect with ASC
Replies: 2
Views: 5514

Interaction effect with ASC

Hi Stephane! I would like to use some sociodemographic variable in my utility function in order to analyse whether they have impact for choosing the opt-out alternative. I saw you use this approach in apollo_example_3: asc_bus_value = asc_bus + asc_bus_shift_female * female asc_air_value = asc_air +...