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 4 matches
- 25 Nov 2022, 19:13
- Forum: Errors during model validation and/or estimation.
- Topic: Issues with MDECV (prediction, outside good and covariates)
- Replies: 3
- Views: 1492
Re: Issues with MDECV (prediction, outside good and covariates)
Stephane, i) these are aggregate predictions, i.e. summing up demand across the whole data. Does that make more sense to you? Yes. But the average predictions are three times smaller than the actual values. Alternatively, I tired to use expenditure as outcomes with price equals to 1; the prediction ...
- 25 Nov 2022, 18:56
- Forum: Errors during model validation and/or estimation.
- Topic: MDCEV model with perhaps budget issue
- Replies: 2
- Views: 2217
Re: MDCEV model with perhaps budget issue
Hi David,
Many thanks for the help! I will contact you later.
Thanks,
Connie
Many thanks for the help! I will contact you later.
Thanks,
Connie
- 16 Nov 2022, 19:29
- Forum: Errors during model validation and/or estimation.
- Topic: Issues with MDECV (prediction, outside good and covariates)
- Replies: 3
- Views: 1492
Issues with MDECV (prediction, outside good and covariates)
Hi Expert, I have three issues with MDCEV estimation. I tried the following three models; each has an issue: i) with outside good + without covariates: the model runs, but prediction is very huge outside the normal range ii) without outside good + without covariates: there is error message: Error in...
- 15 Nov 2022, 20:17
- Forum: Errors during model validation and/or estimation.
- Topic: MDCEV model with perhaps budget issue
- Replies: 2
- Views: 2217
MDCEV model with perhaps budget issue
Hi Experts, I am facing an issue about MDCEV model. There is an error message "Error in if (choicematrix[2, a] == choicematrix[1, a] && inputs$altnames[a] != : missing value where TRUE/FALSE needed". My data has unit price for each alternative and a different budget for different o...