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 11 matches
- 22 Jun 2023, 18:47
- Forum: Other
- Topic: negative sign in the range of log-uniform distribution
- Replies: 1
- Views: 3742
negative sign in the range of log-uniform distribution
Hello Prof. Stephane, I have considered that the coefficients of alternative attributes follows log-uniform distribution by taking the exponential of uniform distribution. But standard deviation, which represents the range of log-uniform distribution is coming out negative in the purchase price vari...
- 16 Apr 2023, 22:28
- Forum: Examples (existing and requests for new ones)
- Topic: Examples given not clear
- Replies: 1
- Views: 4334
Examples given not clear
Hi Stephane,
Can you please make me clear about the difference between the Hybrid_with_OL and Hybrid_LC_with_OL
Thanks,
Yash
Can you please make me clear about the difference between the Hybrid_with_OL and Hybrid_LC_with_OL
Thanks,
Yash
- 16 Apr 2023, 01:22
- Forum: Model specification
- Topic: ICLV model using ordered measurement model for indicators
- Replies: 1
- Views: 777
ICLV model using ordered measurement model for indicators
Hi Stephane, I am replicating the "ICLV ordered logit attitudinal model" used in your paper "Using ordered attitudinal indicators in a latent variable choice model: a study of the impact of security on rail travel behaviour" for my data which has binary choice. Can you please che...
- 29 Mar 2023, 11:58
- Forum: Models and estimation
- Topic: interpretation of ICLV model estimates
- Replies: 4
- Views: 7712
Re: interpretation of ICLV model estimates
Hi Stephane,
The link provided by you for interpreting an ICLV model needs to be fixed. Can you please resend the link?
The link provided by you for interpreting an ICLV model needs to be fixed. Can you please resend the link?
- 20 Mar 2023, 16:15
- Forum: Model estimation
- Topic: ICLV model using ordered measurement model for indicators
- Replies: 2
- Views: 4979
ICLV model using ordered measurement model for indicators
Hi Stephane, I am working on an ICLV model with two latent variables using an ordered measurement model for indicators. Please check if my code is correct. I am getting NaN values; I have tried changing the initial values, but the problem still needs to be solved. Thanks ### Clear memory rm(list = l...
- 14 Mar 2023, 13:29
- Forum: Model estimation
- Topic: Result change drastically when increase halton draws from 1500 to 2000 draws
- Replies: 1
- Views: 4362
Result change drastically when increase halton draws from 1500 to 2000 draws
Hi Stehane, I am considering log-normal distribution in all these results. Why am I getting NaN when I increase the Halton draws to 2000? Also, the parameter estimates change drastically when I change the number of Halton draws from 1500 to 2000. Thanks Estimates: Estimate s.e. t.rat.(0) Rob.s.e. Ro...
- 07 Mar 2023, 10:34
- Forum: Errors during model validation and/or estimation.
- Topic: NaN values in hybrid choice model
- Replies: 3
- Views: 1228
Re: NaN values in hybrid choice model
The reason for fixing tau as zero is that the model could be overspecified. Also, in one of your papers published in 2012 ("Using ordered attitudinal indicators in a latent variable choice model: a study of the impact of security on rail travel behavior"), one tau of each indicator is fixe...
- 05 Mar 2023, 12:29
- Forum: Errors during model validation and/or estimation.
- Topic: NaN values in hybrid choice model
- Replies: 3
- Views: 1228
NaN values in hybrid choice model
Hi Stephane, I have attached my code and result below; this is a hybrid choice model with two choices. I do not know why I am getting NaN values. Can you please look into it? # ################################################################# # #### LOAD LIBRARY AND DEFINE CORE SETTINGS #### # #####...
- 10 Jan 2023, 12:17
- Forum: Estimation results
- Topic: MMNL model with panel data
- Replies: 1
- Views: 3899
MMNL model with panel data
Why I am getting mean and standard deviation of some parameters as statistically insignificant? I have included code and results below please take a look on it. I am working on panel data where there are 4 observations per individual. *****************************************************************...
- 10 Sep 2022, 10:38
- Forum: Errors during model validation and/or estimation.
- Topic: Getting error in Binary logit model
- Replies: 3
- Views: 2232
Re: Getting error in Binary logit model
I forgot to attach the output so I am attaching my console window here -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------...