Dear Professor Stephane,
Thank you very much for your help.
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 13 matches
- 25 Feb 2021, 02:20
- Forum: Post-estimation analysis/use of results
- Topic: Apollo_lrTest
- Replies: 7
- Views: 8624
- 24 Feb 2021, 04:00
- Forum: Post-estimation analysis/use of results
- Topic: Apollo_lrTest
- Replies: 7
- Views: 8624
Re: Apollo_lrTest
Dear Professor Stephane, Thank you very much for your suggestion. I still have a question to make clear my understanding: In our shared model that I accounted for scale difference, parameters specified for each group are random distributed. In case that both mean and sigma of both groups' parameter ...
- 23 Feb 2021, 03:27
- Forum: Post-estimation analysis/use of results
- Topic: Worse LL for general model in MIXL
- Replies: 3
- Views: 5799
Re: Worse LL for general model in MIXL
Dear Professor Stephane, Thank you for your reply. Below image is my estimates: - Restricted Model: LL(start) : -7016.876 LL(0) : -3948.413 LL(final) : -3162.413 Estimated parameters : 23 Iterations : 54 Min abs eigenvalue of Hessian : 10.22751 Estimation method : bfgs Model diagnosis : successful c...
- 22 Feb 2021, 07:49
- Forum: Post-estimation analysis/use of results
- Topic: Worse LL for general model in MIXL
- Replies: 3
- Views: 5799
Worse LL for general model in MIXL
Dear Professor Stephane Hess, I am testing the difference of preference of an attribute between two groups of respondents by LL ratio test for the pooled sample: My restricted model (attributes homogenous between 2 groups): V = beta_x * x + ... My general model (testing if there is a difference of p...
- 19 Feb 2021, 09:50
- Forum: Post-estimation analysis/use of results
- Topic: Apollo_lrTest
- Replies: 7
- Views: 8624
Re: Apollo_lrTest
Dear Professor, For my own estimation, I am focusing on the difference of preference between visitors and households. I want to control for differences in both mean sensitivity and sigmas. My concerns are: - How to choose the attribute having the same sensitivity between two groups to fix it in the ...
- 18 Feb 2021, 00:47
- Forum: Post-estimation analysis/use of results
- Topic: Apollo_lrTest
- Replies: 7
- Views: 8624
Re: Apollo_lrTest
Dear Professor,
I am using version 0.2.2, but I have just updated to 0.2.3 and the function can be run. Thank you.
I am using version 0.2.2, but I have just updated to 0.2.3 and the function can be run. Thank you.
- 17 Feb 2021, 11:39
- Forum: Post-estimation analysis/use of results
- Topic: Apollo_lrTest
- Replies: 7
- Views: 8624
Apollo_lrTest
Dear Professor, I am using Apollo_lrtest to test the restricted and general model with same sample but got this error "Error in apollo_lrTest("MIXL_Pool", "MIXL_Width_Test") : Number of observations not found in MIXL_Pool_output.txt". It can be calculated manually but I...
- 05 Feb 2021, 15:31
- Forum: Errors during model validation and/or estimation.
- Topic: Parameter does not influence the likelihood
- Replies: 7
- Views: 8041
Re: Parameter does not influence the likelihood
Thank you very much Professor Stephane for pointing out this silly mistake of me. It took me weeks to try to understand why I always didnt get normal results in various estimations. Now I know. Thank you.
- 05 Feb 2021, 08:44
- Forum: Errors during model validation and/or estimation.
- Topic: Parameter does not influence the likelihood
- Replies: 7
- Views: 8041
Re: Parameter does not influence the likelihood
Dear Professor Stephane,
I have checked both and they are not the case:
1. 30% subsample has vit=1,
2. facT.1=0 while facT.2 and facT.3 is different. They are dummy variables.
vit*facT.1, vit*facT.2 and vit*facT.3 are also different.
I have checked both and they are not the case:
1. 30% subsample has vit=1,
2. facT.1=0 while facT.2 and facT.3 is different. They are dummy variables.
vit*facT.1, vit*facT.2 and vit*facT.3 are also different.
- 04 Feb 2021, 03:59
- Forum: Errors during model validation and/or estimation.
- Topic: Negative Std Dev, NAs when hessianRoutine="maxLik"
- Replies: 1
- Views: 3924
Negative Std Dev, NAs when hessianRoutine="maxLik"
Dear Professors, I am estimating in Apollo package and find it very flexible and strong package. I enjoy estimating DCE with it. However, I am encountering some problem when estimating MIXL and I would like to ask for your advice if possible: 1. I got negative standard deviation and negative t ratio...