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 5 matches
- 04 Jul 2021, 14:29
- Forum: Model estimation
- Topic: WTP-space estimates in latent class context
- Replies: 14
- Views: 19360
Re: WTP-space estimates in latent class context
Hi Stephane, Here is the code in preference space for the base MNL. and the model output below that. I have calculated WTP from this model used these as starting values but that didn't seem to help. I have also tried starting with 0 and small negative starting value for cost. just to clarify, as far...
- 29 Jun 2021, 15:33
- Forum: Model estimation
- Topic: WTP-space estimates in latent class context
- Replies: 14
- Views: 19360
Re: WTP-space estimates in latent class context
Hi there, I am also having trouble getting my MNL and MMNL DCE model to converge reliably in WTP space. I have fed it different starting values and that didn't seem to help. utility functions are: V[['alt1']] = b_cos * (b_si*sib_2 + b_in*in_2 + b_fen*fen_2 + b_dow*dow_2 + b_hom*hom_2 + b_res*res_2 +...
- 05 Dec 2020, 11:11
- Forum: Errors during model validation and/or estimation.
- Topic: Impact of numDeriv and maxLik on estimating the hessian
- Replies: 3
- Views: 5945
Re: Impact of numDeriv and maxLik on estimating the hessian
Currently I am running Apollo 0.2.1 and the comments above are from working with this version, but I was using 0.0.9 and actually (if I remember correctly i had specified the maxLik package) in this version I didn't have the warnings about positive hessian and nan's for se.
Cheers,
Alaya
Cheers,
Alaya
- 04 Dec 2020, 07:29
- Forum: Errors during model validation and/or estimation.
- Topic: Impact of numDeriv and maxLik on estimating the hessian
- Replies: 3
- Views: 5945
Impact of numDeriv and maxLik on estimating the hessian
Hi, I have been estimating a mixed logit discrete choice model in Apollo and I was receiving errors indicating positivity in the hessian and some NaN's for standard errors while using the maxLik package to estimate the hessian. If I use the numDeriv package the model has stabilised (okay hessian and...
- 02 Nov 2020, 05:47
- Forum: Post-estimation analysis/use of results
- Topic: Calculating Standard Deviations for Correlated Random Parameters mnl
- Replies: 1
- Views: 3668
Calculating Standard Deviations for Correlated Random Parameters mnl
Hi,
I'm sure there is a simple Apollo solution, but I am having trouble finding it, to calculate the standard deviations (and their se) for correlated random parameters in a mixlogit discrete choice model.
Cheers
I'm sure there is a simple Apollo solution, but I am having trouble finding it, to calculate the standard deviations (and their se) for correlated random parameters in a mixlogit discrete choice model.
Cheers