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 12 matches
- 18 Jan 2022, 09:09
- Forum: Post-estimation analysis/use of results
- Topic: Mean and SD of lognormal attribute correlated with another attribute
- Replies: 4
- Views: 3706
Re: Mean and SD of lognormal attribute correlated with another attribute
Thank you for clearing that out..
- 17 Jan 2022, 12:15
- Forum: Post-estimation analysis/use of results
- Topic: Mean and SD of lognormal attribute correlated with another attribute
- Replies: 4
- Views: 3706
Re: Mean and SD of lognormal attribute correlated with another attribute
Thank you for the prompt reply,
One more thing
Does the correlation term s1_2 comes somewhere in the analytical formula?
I know generally we use mean= exp(m + s^2/2), but its the correlation parameter s1_2 that’s confusing me.
One more thing
Does the correlation term s1_2 comes somewhere in the analytical formula?
I know generally we use mean= exp(m + s^2/2), but its the correlation parameter s1_2 that’s confusing me.
- 17 Jan 2022, 10:07
- Forum: Post-estimation analysis/use of results
- Topic: Mean and SD of lognormal attribute correlated with another attribute
- Replies: 4
- Views: 3706
Mean and SD of lognormal attribute correlated with another attribute
Hi all, If I have two attributes of time: lognormally distributed and correlated as following: time1 <- -exp(m1 + s1 * draws1) time2 <- -exp(m2 + s2 * draws2 + s1_2 * draws1) Now if I want to find the mean and sd for the random variable time2 , is this the correct way of doing that? Find the uncondi...
- 03 Aug 2021, 03:00
- Forum: Data preparation, processing and pre-estimation analysis
- Topic: Hybrid choice model structural part.
- Replies: 1
- Views: 6357
Hybrid choice model structural part.
Hello, everyone I have a very simple question on structural equation part of the hybrid model. While specifying the structural part of latent variable as random coefficients is it fine to just use the normal draws. For example I have interNormalDraws = c("eta") ## Now in random coefficient...
- 16 Mar 2021, 23:29
- Forum: Model specification
- Topic: Elasticity with random parameter in mixed logit.
- Replies: 6
- Views: 8115
Re: Elasticity with random parameter in mixed logit.
Yes that does makes perfect sense. Thank you
- 11 Mar 2021, 22:27
- Forum: Model specification
- Topic: Elasticity with random parameter in mixed logit.
- Replies: 6
- Views: 8115
Re: Elasticity with random parameter in mixed logit.
Thankyou for your valuable insights, i wanted to add a quick simple theoretical question (assuming the cost attribute is still normal), Does addition of the term to capture an income elasticity as mentioned by doing [([B_cost + sigma_cost * normal ) * (income)^B_inc] means we are changing the distri...
- 05 Mar 2021, 00:36
- Forum: Model specification
- Topic: Elasticity with random parameter in mixed logit.
- Replies: 6
- Views: 8115
Elasticity with random parameter in mixed logit.
I have a question regarding the utility equation for understanding the elasticity in mixed logit model. I can think of two ways of including elasticity, suppose i have a utility equation with time and cost and income. 1) U = B_time * Travel time + [([B_cost + sigma_cost * normal ) * (income)^B_inc] ...
- 24 Feb 2021, 20:21
- Forum: Models and estimation
- Topic: Best way to model directly correlated attributes.
- Replies: 3
- Views: 5918
Re: Best way to model directly correlated attributes.
Thank you for the swift response Dr. Hess, what do you mean by test the difference between parameters in last part?
- 24 Feb 2021, 08:33
- Forum: Models and estimation
- Topic: Best way to model directly correlated attributes.
- Replies: 3
- Views: 5918
Best way to model directly correlated attributes.
Hello everyone, I am running a mixed logit model from unlabeled stated choice experiment with four attributes. I will try to explain in general a similar situation to my problem. 1) Attribute A 2) Attribute B 3) Cash back 4) Total Cost Now i can think of three ways to estimate the parameters a) Keep...
- 06 Feb 2021, 22:50
- Forum: Examples (existing and requests for new ones)
- Topic: Hybrid choice modelling.
- Replies: 4
- Views: 9704
Re: Hybrid choice modelling.
Thankyou Dr Hess for the clearance,
I think my use of words were confusing, but your explanation makes it clear.
I think my use of words were confusing, but your explanation makes it clear.