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 7 matches
- 13 Jul 2021, 02:37
- Forum: Data preparation, processing and pre-estimation analysis
- Topic: Structuring a dataset with forced choice followed by unforced/opt-out
- Replies: 9
- Views: 13259
Re: Structuring a dataset with forced choice followed by unforced/opt-out
Hi Stephane, (1) I don't think it makes sense to model both follow-up questions, since participants only saw one of the questions, based on which Program they selected (i.e. based on the question logic, they would only see Q5.11 if in the previous question they selected Program A, and only see Q5.12...
- 10 Jul 2021, 01:03
- Forum: Data preparation, processing and pre-estimation analysis
- Topic: Structuring a dataset with forced choice followed by unforced/opt-out
- Replies: 9
- Views: 13259
Re: Structuring a dataset with forced choice followed by unforced/opt-out
Hi Stephane, This is the code I used for an MNL with the forced choice model, using these data https://osf.io/jfz5h ### Load libraries library(here) library(readr) library(apollo) library(dplyr) ### Initialise code apollo_initialise() ### Set core controls apollo_control<-list( modelName= "dce_...
- 08 Jul 2021, 00:49
- Forum: Data preparation, processing and pre-estimation analysis
- Topic: Structuring a dataset with forced choice followed by unforced/opt-out
- Replies: 9
- Views: 13259
Re: Structuring a dataset with forced choice followed by unforced/opt-out
Hi Stephane, I am not sure if I have understood your comments. As the data are currently structured, I do have one row per choice (Column C: task) with the choice between two programs (Column D: choice_forced) and the choice between the selected program and the treatment (Column E: choice_tx). At pr...
- 21 Jun 2021, 16:09
- Forum: Data preparation, processing and pre-estimation analysis
- Topic: Structuring a dataset with forced choice followed by unforced/opt-out
- Replies: 9
- Views: 13259
Re: Structuring a dataset with forced choice followed by unforced/opt-out
Hi Stephane! Thanks for your response; yes, the suggestion you made below is the direction we would like to go in. Greatly appreciate your assistance My-Linh Hi this depends entirely on what you want to do in your model. Are you wanting to jointly model the choice of the preferred programme and then...
- 12 Jun 2021, 00:55
- Forum: Data preparation, processing and pre-estimation analysis
- Topic: Structuring a dataset with forced choice followed by unforced/opt-out
- Replies: 9
- Views: 13259
Structuring a dataset with forced choice followed by unforced/opt-out
Hello there, I was interested to know how to code a dataset that presents the participant with a forced choice (Program A or Program B), followed by an opportunity to opt-out (Program A or not participate at all, Program B or not participate at all). The DCE_forced and opt-out image shows what the p...
- 05 May 2021, 18:21
- Forum: Errors during model validation and/or estimation.
- Topic: Error in apollo_validateData when running Apollo_example_3.r code
- Replies: 1
- Views: 3705
Error in apollo_validateData when running Apollo_example_3.r code
Hello, I ran into the following error when I was running code that modelled that of the Apollo_example_3.r "Error in apollo_validateData(database, apollo_control, silent = silent) : All rows for the same individual should be next to each other in the data!" I reviewed my dataset to make su...
- 05 May 2021, 01:07
- Forum: Errors during model validation and/or estimation.
- Topic: Input validation code works on other PC, not mine
- Replies: 16
- Views: 47065
Re: Input validation code works on other PC, not mine
Hi there, I am running into the same error as the members above (i.e. Error in apollo_validateData(database, apollo_control, silent = silent) : All rows for the same individual should be next to each other in the data!) I believe my data are in the correct wide format with all the rows next to each ...