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 998 matches
- 24 Apr 2024, 15:36
- Forum: Post-estimation analysis/use of results
- Topic: delta method to calculate WTP (normal and log-normal parameters)
- Replies: 10
- Views: 13484
Re: delta method to calculate WTP (normal and log-normal parameters)
yes, that's correct
- 24 Apr 2024, 15:35
- Forum: Estimation results
- Topic: Low t-ratios in MNL
- Replies: 1
- Views: 25
Re: Low t-ratios in MNL
Hi
there could be many reasons for this. Either there really is no effect (in which case that is a finding), or you don't have enough data, or a bad design. But this is a general question, not Apollo related
Stephane
there could be many reasons for this. Either there really is no effect (in which case that is a finding), or you don't have enough data, or a bad design. But this is a general question, not Apollo related
Stephane
- 24 Apr 2024, 15:33
- Forum: Data preparation, processing and pre-estimation analysis
- Topic: deal with Missing data
- Replies: 1
- Views: 12
Re: deal with Missing data
Hi
you can either impute them, or estimate a separate effect for those people
Stephane
you can either impute them, or estimate a separate effect for those people
Stephane
- 24 Apr 2024, 15:31
- Forum: Post-estimation analysis/use of results
- Topic: Marginal rate of substitution for different sociodemographic groups
- Replies: 3
- Views: 186
Re: Marginal rate of substitution for different sociodemographic groups
Hi
your unconditional distributions will not be different for people with different socio-demographics unless you have included the interactions in apollo_randCoeff. So subsetting the data will not do anything
Stephane
your unconditional distributions will not be different for people with different socio-demographics unless you have included the interactions in apollo_randCoeff. So subsetting the data will not do anything
Stephane
- 24 Apr 2024, 15:29
- Forum: Post-estimation analysis/use of results
- Topic: WTP for mixed logit with random parameters
- Replies: 24
- Views: 32234
Re: WTP for mixed logit with random parameters
Hi the delta method in Apollo is for individual model parameters, not for distributed coefficients. In your case, you would need to use apollo_unconditionals to obtain the draws for the coefficients and calculate WTP moments that way, but you would not be able to use apollo_deltaMethod as you cannot...
- 24 Apr 2024, 15:27
- Forum: Errors during model validation and/or estimation.
- Topic: error in getiing Standarad error of e mdcev model
- Replies: 3
- Views: 56
Re: error in getiing Standarad error of e mdcev model
Hi
it's not clear what you mean exactly. Do you want to interact this with covariates?
Stephane
it's not clear what you mean exactly. Do you want to interact this with covariates?
Stephane
- 24 Apr 2024, 15:26
- Forum: Post-estimation analysis/use of results
- Topic: how to make probability plot in E MDCEV MODEL
- Replies: 1
- Views: 29
Re: how to make probability plot in E MDCEV MODEL
Hi
you can make predictions from a model in Apollo. This will produce a prediction for each row in the data, and then you can of course use standard R functions to product plots
Stephane
you can make predictions from a model in Apollo. This will produce a prediction for each row in the data, and then you can of course use standard R functions to product plots
Stephane
- 24 Apr 2024, 15:19
- Forum: Model specification
- Topic: Accounting for stochastic variables in discrete choice models
- Replies: 1
- Views: 26
Re: Accounting for stochastic variables in discrete choice models
Julia
this should only be needed in situations where you have uncertainty about the attributes
Stephane
this should only be needed in situations where you have uncertainty about the attributes
Stephane
- 24 Apr 2024, 09:49
- Forum: Estimation results
- Topic: Missing model-fit parameters
- Replies: 3
- Views: 189
Re: Missing model-fit parameters
Hi
if you share your code and data with me outside the forum, I'll have a look
Stephane
if you share your code and data with me outside the forum, I'll have a look
Stephane
- 22 Apr 2024, 13:40
- Forum: Examples (existing and requests for new ones)
- Topic: Heterogeneous alternative choice set
- Replies: 1
- Views: 44
Re: Heterogeneous alternative choice set
hi
the closest we have to this would be http://apollochoicemodelling.com/files/ ... e_coding.r where you could easily add availabilities too
Stephane
the closest we have to this would be http://apollochoicemodelling.com/files/ ... e_coding.r where you could easily add availabilities too
Stephane