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  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
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Search found 7 matches

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by Julián
24 Apr 2025, 15:22
Forum: Errors during model validation and/or estimation.
Topic: Error in estimates in MDCEV
Replies: 1
Views: 19527

Error in estimates in MDCEV

Dear Profesors,

Thanks for developing such a powerful tool.

I am trying to estimate a MDCEV model. However, I got the following error message:

model = apollo_estimate(apollo_beta, apollo_fixed, apollo_probabilities, apollo_inputs)
Preparing user-defined functions.
Error en if (!test) {: valor ...
by Julián
12 Dec 2024, 23:00
Forum: Post-estimation analysis/use of results
Topic: Limitations of market share forecasts with SP data
Replies: 5
Views: 35431

Re: Limitations of market share forecasts with SP data

Dear Professor,

I am using SP data to estimate a mode choice model (road vs SSS) with MDCEV. I have the market shares revealed by the decision-makers to make predictions. We would like to use them to correct the ASCs from SP estimates.

How can we do that in MDCEV in Apollo? I do not know how to ...
by Julián
09 Sep 2024, 12:16
Forum: Model estimation
Topic: MDCEV RP_SP: identification problem
Replies: 3
Views: 28654

Re: MDCEV RP_SP: identification problem

Hi Stephane,

Thank you very much! I have already shared the code and data with you.

Regards,

Stephane
by Julián
01 Sep 2024, 16:58
Forum: Model estimation
Topic: MDCEV RP_SP: identification problem
Replies: 3
Views: 28654

MDCEV RP_SP: identification problem

Hi Professors,

I have a mode choice experiment data with two alternatives. I like to make a joint estimation of RP and SP data in MDCEV. I have followed the code example MNL_RP_SP and I have tried to adapt it for the MDCEV, but I am not sure if it is ok. I got the following message:

Error en ...
by Julián
09 Jun 2024, 22:37
Forum: Data preparation, processing and pre-estimation analysis
Topic: MDCEV with price attribute
Replies: 5
Views: 37604

Re: MDCEV with price attribute

Hi Stephane,
Thank you for your reply. After that, I realised that the definition of the budget was not correct. So, I changed it (price x quantity) and, then it worked.

However, it does not reach convergence with the "bgw" estimation method. For comparison purpose, I run the MDCEV for the ...
by Julián
29 May 2024, 18:59
Forum: Data preparation, processing and pre-estimation analysis
Topic: MDCEV with price attribute
Replies: 5
Views: 37604

Re: MDCEV with price attribute

Hi Stephane,

Thank you for your response.

I did what you recommended and I got this message:

Error en apollo_validate(mdcev_settings, modelType, functionality, apollo_inputs):
INPUT ISSUE - Expenditure for some observations for model component "model" is either less or more than budget!

We ...
by Julián
24 May 2024, 14:50
Forum: Data preparation, processing and pre-estimation analysis
Topic: MDCEV with price attribute
Replies: 5
Views: 37604

MDCEV with price attribute

Dear Professors,

I am trying to estimate MDCEV model with my SP data for mode choice. In my dataset, each choice has a price attribute. The price attribute varies along individual, among individuals and alternatives

By checking the sample data and code provided in Apollo website for the MDCEV, the ...

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