Important: Read this before posting to this forum
- 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.
- 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
- Before asking a question on the forum, users are kindly requested to follow these steps:
- Check that the same issue has not already been addressed in the forum - there is a search tool.
- 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
- Check the frequently asked questions section on the Apollo website, which discusses some common issues/failures. Please see http://www.apollochoicemodelling.com/faq.html
- Make sure that R is using the latest official release of Apollo.
- Users can check which version they are running by entering packageVersion("apollo").
- Then check what is the latest full release (not development version) at http://www.ApolloChoiceModelling.com/code.html.
- To update to the latest official version, just enter install.packages("apollo"). To update to a development version, download the appropriate binary file from http://www.ApolloChoiceModelling.com/code.html, and install the package from file
- If the above steps do not resolve the issue, then users should follow these steps when posting a question:
- provide full details on the issue, including the entire code and output, including any error messages
- 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
- 01 Feb 2022, 14:28
- Forum: Model specification
- Topic: Nested Logit - fixed lambda (NNNL vs. UMNL)
- Replies: 12
- Views: 7716
Re: Nested Logit - fixed lambda (NNNL vs. UMNL)
Now it's clear. Thanks again Stephane!
- 25 Jan 2022, 18:52
- Forum: Model specification
- Topic: Nested Logit - fixed lambda (NNNL vs. UMNL)
- Replies: 12
- Views: 7716
Re: Nested Logit - fixed lambda (NNNL vs. UMNL)
Stephane,
Could you please give me some guidance or refer me to an example of how to implement this in Apollo?
Many thanks
Bartosz
Could you please give me some guidance or refer me to an example of how to implement this in Apollo?
Many thanks
Bartosz
- 18 Jan 2022, 17:15
- Forum: Model specification
- Topic: Nested Logit - fixed lambda (NNNL vs. UMNL)
- Replies: 12
- Views: 7716
Re: Nested Logit - fixed lambda (NNNL vs. UMNL)
Stephane thanks again for looking at this. I'm still not clear what you are trying to do here exactly, or why you want a nested logit model for it. Nested logit is not a model of sequential choice behaviour. So it would not model the choice of tour type followed by mode, as the dependent variable in...
- 11 Jan 2022, 09:47
- Forum: Model specification
- Topic: Nested Logit - fixed lambda (NNNL vs. UMNL)
- Replies: 12
- Views: 7716
Re: Nested Logit - fixed lambda (NNNL vs. UMNL)
Stephane Thank you very much for having a look at the data and pointing out the problems with my model. You are correct, the attributes do not differ between simple and complex tours because I do not suppose that people perceive time and cost in a different way depending on how complex their daily s...
- 07 Jan 2022, 08:39
- Forum: Model specification
- Topic: Nested Logit - fixed lambda (NNNL vs. UMNL)
- Replies: 12
- Views: 7716
Re: Nested Logit - fixed lambda (NNNL vs. UMNL)
Of course, you should have it on your mailbox already.
Thanks again for your time.
Bartosz
Thanks again for your time.
Bartosz
- 05 Jan 2022, 11:21
- Forum: Model specification
- Topic: Nested Logit - fixed lambda (NNNL vs. UMNL)
- Replies: 12
- Views: 7716
Re: Nested Logit - fixed lambda (NNNL vs. UMNL)
Stephane, thank you for clarifying the issue of normalizing the lambdas and NL versions. The reason I was concerned about this fixing of one of the lambdas to 1 was because: without fixing, I obtain absolutely crazy results: Model name : TNL_1.1_summer Model description : Tour-based NL model with TT...
- 21 Dec 2021, 18:41
- Forum: Model specification
- Topic: Nested Logit - fixed lambda (NNNL vs. UMNL)
- Replies: 12
- Views: 7716
Nested Logit - fixed lambda (NNNL vs. UMNL)
I am working on a tour-based model for transport mode choice, and want to use Nested Logit to replicate the relationship between tour complexity and mode choice, as shown below: NL structure.png Given that I have two nests, there are two nesting parameters *lambda* to be estimated - lambda_simple an...
- 20 Nov 2021, 09:29
- Forum: Model specification
- Topic: Simultaneous estimation of parameters with potentially different scale
- Replies: 10
- Views: 17018
Re: Simultaneous estimation of parameters with potentially different scale
Thanks Stephane!
Bartosz
Bartosz
- 18 Nov 2021, 14:13
- Forum: Model specification
- Topic: Simultaneous estimation of parameters with potentially different scale
- Replies: 10
- Views: 17018
Re: Simultaneous estimation of parameters with potentially different scale
Hi, If I may bump this topic, I would like to ask about the scale parameter (as in example_22). Following the "artificial tree structure" approach by Bradley and Daly (1992) ro Louviere et al. (2000), is the parameter that we get from Apollo, the inclusive value of the "nest" , w...