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
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Search found 9 matches

by Blake Huang
08 Apr 2022, 12:51
Forum: Data
Topic: Data set with missing values
Replies: 7
Views: 7904

Re: Data set with missing values

That's exactly how I deal with it. I just want to make sure it's the right way to do it. Thank you, Prof. Hess.
by Blake Huang
05 Apr 2022, 14:02
Forum: Data
Topic: Data set with missing values
Replies: 7
Views: 7904

Re: Data set with missing values

Dear Prof. Hess, This is my model specification, and you can check the attachment for the complete data format. V[['alt1']] = asc_1 + b_tt * cartime + b_pollution * carpollution V[['alt2']] = asc_2 + b_tt * prtime + b_fee * prfee + b_capacity_2 * capacity + b_comfort2_2 * comfort2 + b_comfort3_2 * c...
by Blake Huang
05 Apr 2022, 03:26
Forum: Data
Topic: Data set with missing values
Replies: 7
Views: 7904

Re: Data set with missing values

Hi, Prof. Hess, I am very sorry for not describing my problem clearly. For example, let's assume that each respondent is required to complete 18 (9+9) hypothetical scenarios. Scenario 1-9: including 8 attributes, and then 9 scenarios are obtained through uniform design. Scenario 10-18: including 10 ...
by Blake Huang
03 Apr 2022, 11:08
Forum: Data
Topic: Data set with missing values
Replies: 7
Views: 7904

Data set with missing values

Hello Prof. Hess, My data set inherently has missing values. I designed 9 SP scenarios with different variables between each 3 scenarios, but the alternatives are the same for all scenarios. For example, I considered 3 variables in Scenario 1-3, 2 additional variables in Scenario 4-6, and 3 addition...
by Blake Huang
08 Jul 2021, 10:56
Forum: Post-estimation analysis/use of results
Topic: MNL model- elasticity calculations
Replies: 2
Views: 4322

Re: MNL model- elasticity calculations

Dear Prof Hess,

Thank you very much for your quick reply!

Yue
by Blake Huang
08 Jul 2021, 08:03
Forum: Post-estimation analysis/use of results
Topic: MNL model- elasticity calculations
Replies: 2
Views: 4322

MNL model- elasticity calculations

Hi, prof Hess, I met a mistake when attempting to calculate the elasticity in the MNL model. Here is the warning: WARNING: Element database in the global environment differs from that inside apollo_inputs. The latter will be used. If you wish to use the former, stop this function by pressing the &qu...
by Blake Huang
01 May 2021, 16:40
Forum: Model estimation
Topic: A simple question related to ICLV model
Replies: 3
Views: 6943

Re: A simple question related to ICLV model

Thanks for the prompt reply prof Hess! I have solved the problem with your help. Another question is that after the estimation process, only the coefficients of the variables are given, and other results always being calculating. Could this be related to the hardware of the computer?
by Blake Huang
25 Apr 2021, 11:14
Forum: Model estimation
Topic: A simple question related to ICLV model
Replies: 3
Views: 6943

A simple question related to ICLV model

Hi, Prof. Hess, I encountered a problem in estimating the ICLV model. We all know that sometimes, not all values in attitudinal indicators are selected. For example, in my study, no one chooses 1 in the indicator variable “CA1”. Then, the model reported an error message: Some levels in "coding&...
by Blake Huang
08 Dec 2020, 12:13
Forum: Model specification
Topic: Mixed Logit Model with inter and intra individual heterogeneity
Replies: 1
Views: 3782

Mixed Logit Model with inter and intra individual heterogeneity

Dear sir or madam, I am using Apollo to analyze my data by applying a mixed logit model. The MMNL model in my study should deal with both the heterogeneity across individuals and the heterogeneity across repeated choices for the same individual (panel mixed logit model). However, i am a little confu...