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 27 matches

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by svenne
17 Jul 2023, 10:09
Forum: Post-estimation analysis/use of results
Topic: Function to create tree from nested logit
Replies: 2
Views: 3042

Re: Function to create tree from nested logit

Yep. Something we are currently working on (nest and assignment coefficients)
by svenne
17 Jul 2023, 10:08
Forum: Post-estimation analysis/use of results
Topic: Generate LaTeX code of utility functions
Replies: 2
Views: 3196

Re: Generate LaTeX code of utility functions

No, we didn't. Moreover, the function does not work for aliases, like

composite_constant = asc + beta * age

v = composite_constant + alpha * cost

.

Something for the future ...
by svenne
12 Jul 2023, 13:42
Forum: Post-estimation analysis/use of results
Topic: Generate LaTeX code of utility functions
Replies: 2
Views: 3196

Generate LaTeX code of utility functions

Dear users, we have written a function that generates LaTeX code of the utility functions given a model object input. Please fee free to test and report bugs etc . Find the function here: https://git.rwth-aachen.de/data-business-analytics-rwth-aachen-2023/testvisibility/-/blob/main/mathematical_expr...
by svenne
12 Jul 2023, 13:39
Forum: Post-estimation analysis/use of results
Topic: Function to create tree from nested logit
Replies: 2
Views: 3042

Function to create tree from nested logit

Dear users, we have written a function that generates tree output in R and as LaTeX/tikz code given a model object input. Please fee free to test and report bugs etc . Find the function here: https://git.rwth-aachen.de/data-business-analytics-rwth-aachen-2023/testvisibility/-/blob/main/create_tree.R...
by svenne
07 Mar 2022, 09:29
Forum: Feature requests
Topic: IIA
Replies: 8
Views: 22299

Re: IIA

Hi Mohammed,

yes, sub.m and full.m are the model object names. What makes the code not work?

Best
Sven
by svenne
07 Oct 2021, 10:36
Forum: Models and estimation
Topic: Elasticities in MNL
Replies: 5
Views: 10056

Re: Elasticities in MNL

Hi Stephane,

thanks a lot for getting back.

Best
Sven
by svenne
04 Oct 2021, 16:24
Forum: Models and estimation
Topic: Elasticities in MNL
Replies: 5
Views: 10056

Re: Elasticities in MNL

Dears,

This is an interesting issue. I wonder whether there is a textbook or any other reference that discusses the relationship between the elasticity at the individual level and the market level (total demand)?
Any hint is appreciated.

Best
Sven
by svenne
07 Jul 2021, 12:40
Forum: Feature requests
Topic: IIA
Replies: 8
Views: 22299

Re: IIA

If I remember right, hmft is compared to the critical value from the X^2 with the respective degree of freedom (i.e., 1): qchisq(hmft,1), I think it is. If hmft is larger than this value, the two models are considered to be different, i.e., IIA does not hold.
Does this help?
Best,
Sven
by svenne
12 May 2021, 16:15
Forum: Model specification
Topic: Multi-Level Cross-Nested / Network GEV
Replies: 2
Views: 4379

Re: Multi-Level Cross-Nested / Network GEV

Stephane,

Thank you so much for letting me know.

Best
Sven
by svenne
30 Apr 2021, 16:02
Forum: Model specification
Topic: Multi-Level Cross-Nested / Network GEV
Replies: 2
Views: 4379

Multi-Level Cross-Nested / Network GEV

Dear all,

is it possible to specify a multi-level cross-nested logit in Apollo? For instance,

N1: alpha1*bus, car
N2: alpha2*bus, N3
N3: air, rail

I do not know how to map this nest structure in the matrix for cnlStructure.

Any help is appreciated.

Best
Sven

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