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- 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
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- Check the frequently asked questions section on the Apollo website, which discusses some common issues/failures. Please see http://www.apollochoicemodelling.com/faq.html
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- 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
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Search found 974 matches
- 23 Feb 2024, 11:32
- Forum: Estimation results
- Topic: Unreasonable estimate for price and other attributes
- Replies: 5
- Views: 640
Re: Unreasonable estimate for price and other attributes
Hi Cuong You have 3 alternatives, but you are only estimating one constant. You can estimate J-1 constants, i.e. 2 My question was whether your third alternative in the survey is different from the other two, i.e. does it use different levels, etc? Regarding categorical, what I mean is that you dumm...
- 23 Feb 2024, 11:26
- Forum: Model specification
- Topic: Start values for wta parameter
- Replies: 1
- Views: 152
Re: Start values for wta parameter
Anat
Can you provide us with a bit more detail, please, e.g. a screenshot of a SC task?
Thanks
Stephane
Can you provide us with a bit more detail, please, e.g. a screenshot of a SC task?
Thanks
Stephane
- 23 Feb 2024, 11:22
- Forum: Estimation results
- Topic: MNL Model Estimation with covariate in WTP Space - Difficulty including covariate and to check correctness
- Replies: 1
- Views: 107
Re: MNL Model Estimation with covariate in WTP Space - Difficulty including covariate and to check correctness
Nico if you look at your partial derivatives of the utility functions, you will see that they are now different for the non price attributes given that you have placed the age interaction with cost on the parameter b_price_value so now you are introducing scale heterogeneity as a function of age. On...
- 23 Feb 2024, 11:12
- Forum: Post-estimation analysis/use of results
- Topic: WTP distribution in preference space
- Replies: 1
- Views: 166
Re: WTP distribution in preference space
Hi
Yes, a ratio of two lognormals is a lognormals, and if one (and only one) of the two is a negative lognormal, then the ratio is negative lognormal too
Re your plots, are you using a low number of draws? Maybe also try without imposing the limits
Stephane
Yes, a ratio of two lognormals is a lognormals, and if one (and only one) of the two is a negative lognormal, then the ratio is negative lognormal too
Re your plots, are you using a low number of draws? Maybe also try without imposing the limits
Stephane
- 23 Feb 2024, 11:08
- Forum: Model specification
- Topic: ICLV model specification in unlabelled form
- Replies: 6
- Views: 6027
Re: ICLV model specification in unlabelled form
Hi
In order for us to help you, you need to show us the output, i.e. the parameter estimates.
Can you please also confirm that a MNL and mixed logit model worked on the data before moving to hybrid choice?
Thanks
In order for us to help you, you need to show us the output, i.e. the parameter estimates.
Can you please also confirm that a MNL and mixed logit model worked on the data before moving to hybrid choice?
Thanks
- 06 Feb 2024, 19:56
- Forum: Estimation results
- Topic: Unreasonable estimate for price and other attributes
- Replies: 5
- Views: 640
Re: Unreasonable estimate for price and other attributes
Hi
first, you should always use a full set (i.e. J-1) alternative specific constants.
But is your third alternative systematically different from the other two which could lead to the issues you're seeing
Stephane
first, you should always use a full set (i.e. J-1) alternative specific constants.
But is your third alternative systematically different from the other two which could lead to the issues you're seeing
Stephane
- 03 Feb 2024, 14:05
- Forum: Model estimation
- Topic: Estimation of MNL and MMNL in WTP space issues
- Replies: 5
- Views: 779
Re: Estimation of MNL and MMNL in WTP space issues
Hi
I also need to know the LL you get with MNL and in WTP space, please, i.e. where it runs out of iterations
Stephane
I also need to know the LL you get with MNL and in WTP space, please, i.e. where it runs out of iterations
Stephane
- 01 Feb 2024, 11:15
- Forum: Model estimation
- Topic: Estimation of MNL and MMNL in WTP space issues
- Replies: 5
- Views: 779
Re: Estimation of MNL and MMNL in WTP space issues
Hi
did you first try a model in preference space?
Stephane
did you first try a model in preference space?
Stephane
- 31 Jan 2024, 10:51
- Forum: Estimation results
- Topic: Interpretation of coefficients
- Replies: 3
- Views: 500
Re: Interpretation of coefficients
1. Again, it depends on the units. Imagine that I have b_cost = -0.1 and b_time = -0.05. You can't say that cost matters more than time as it depends on the units. Imagine that cost is in € and time is in minutes. Then what the above is telling us is that €1 is more important than 1 minute, but obvi...
- 30 Jan 2024, 16:00
- Forum: Model specification
- Topic: Nested Logit-location choice joint with mode utility
- Replies: 1
- Views: 612
Re: Nested Logit-location choice joint with mode utility
Hi
I think the reason your model is not working at the moment is that you only have constants in the utilities, which makes it impossible to estimate a nesting structure
Regarding your second question, can you explain a bit more what you mean, please?
Thanks
I think the reason your model is not working at the moment is that you only have constants in the utilities, which makes it impossible to estimate a nesting structure
Regarding your second question, can you explain a bit more what you mean, please?
Thanks