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
- 12 May 2022, 16:59
- Forum: Errors during model validation and/or estimation.
- Topic: All observations have zero probability at starting value for model component
- Replies: 6
- Views: 3145
Re: All observations have zero probability at starting value for model component
Thank you so much Stephane! I tried with delta = -1 as starting value and it worked. My model is a little bit fuzzy on the individual ID, as I am assigning housing units to different locations. So here my "individual" is actually each structure type and I have the observation for around 20...
- 10 May 2022, 22:40
- Forum: Errors during model validation and/or estimation.
- Topic: All observations have zero probability at starting value for model component
- Replies: 6
- Views: 3145
Re: All observations have zero probability at starting value for model component
I think I can partly answer for myself now. My preliminary code is running fine now with these two changes: 1. I changed the individualID as simply 1,2,3,.. and then removed the panel feature in apollo function. 2. I removed delta in apollo_beta as this parameter does not influence the loglikelihood...
- 06 May 2022, 20:06
- Forum: Errors during model validation and/or estimation.
- Topic: All observations have zero probability at starting value for model component
- Replies: 6
- Views: 3145
Re: All observations have zero probability at starting value for model component
Hi Stephane, Thank you for replying! My alternatives are 2057 locations, each alternative has 11 attributes (accessibility, housing price, etc.) but now I am just testing with one attribute (accessibility, indicated as ACAR in the code). I tried a positve gamma just now and the error shows as "...
- 06 May 2022, 19:46
- Forum: Errors during model validation and/or estimation.
- Topic: All observations have zero probability at starting value for model component
- Replies: 6
- Views: 3145
All observations have zero probability at starting value for model component
Hi there, I am running a MDCEV model on location choice dataset and at first I ran into an error as "Log-likelihood calculation fails at values close to the starting values!" so I changed some starting values and now I am getting this eror: Error in if (all(testL == 0)) stop("All obse...
- 05 May 2022, 21:15
- Forum: Errors during model validation and/or estimation.
- Topic: MDCEV model estimation - Budget not as a vector the same size as observation error
- Replies: 1
- Views: 1604
MDCEV model estimation - Budget not as a vector the same size as observation error
Hi, I am getting an error saying that the budget in my MDCEV model specification should be a scalar or a vector the same size as the observations. "Error in apollo_preprocess(mdcev_settings, modelType, functionality, apollo_inputs) : "budget" for model component "MDCEV" shou...