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 21 matches
- 10 May 2024, 10:53
- Forum: Estimation results
- Topic: Positive price coefficient in RPL model estimation
- Replies: 10
- Views: 383
Re: Positive price coefficient in RPL model estimation
Thank you very much for your help Stephane!
- 08 May 2024, 18:42
- Forum: Estimation results
- Topic: Positive price coefficient in RPL model estimation
- Replies: 10
- Views: 383
Re: Positive price coefficient in RPL model estimation
I work with 4 attributes:
1. price (I defined a negative lognormal distribution)
2. brand (I defined a normal distribution)
3. country of origin (I defined a normal distribution)
4. presence of sustainability label (I defined a normal distribution)
1. price (I defined a negative lognormal distribution)
2. brand (I defined a normal distribution)
3. country of origin (I defined a normal distribution)
4. presence of sustainability label (I defined a normal distribution)
- 07 May 2024, 18:37
- Forum: Estimation results
- Topic: Positive price coefficient in RPL model estimation
- Replies: 10
- Views: 383
Re: Positive price coefficient in RPL model estimation
Thank you for your reply Stephane!
What do you mean that the normal distribution has no sense? Isn't this only true for attributes such as cost, travel time, etc.?
What do you mean that the normal distribution has no sense? Isn't this only true for attributes such as cost, travel time, etc.?
- 06 May 2024, 16:14
- Forum: Estimation results
- Topic: Positive price coefficient in RPL model estimation
- Replies: 10
- Views: 383
Re: Positive price coefficient in RPL model estimation
Hi Stephane!
Thank you very much!
Unfortunately, I had to apply a normal distribution to all other attributes except for the price.
In that case, perhaps it is easier to estimate the model in WTP space?
David
Thank you very much!
Unfortunately, I had to apply a normal distribution to all other attributes except for the price.
In that case, perhaps it is easier to estimate the model in WTP space?
David
- 05 May 2024, 19:22
- Forum: Estimation results
- Topic: Positive price coefficient in RPL model estimation
- Replies: 10
- Views: 383
Re: Positive price coefficient in RPL model estimation
Hi Stephane! Thank you very much for your answer, it is now clear and I was able to determine the true average using the unconditional function. I would like to ask that I can also do the WTP calculations with the unconditional function, e.g. wtp=unconditionals[[["b_attribute"]]/unconditio...
- 04 May 2024, 19:37
- Forum: Estimation results
- Topic: Positive price coefficient in RPL model estimation
- Replies: 10
- Views: 383
Positive price coefficient in RPL model estimation
Hi! I would like to ask why I can estimate a positive parameter for the price coefficient for a random parameter logit specification? For the basic MNL model I estimate a negative coefficient, all results are correct, but for RPL whatever I do, the coefficient is always positive. I specify the rando...
- 25 Oct 2022, 09:56
- Forum: Estimation results
- Topic: Positive alternative specific constant for the opt-out
- Replies: 1
- Views: 4361
Positive alternative specific constant for the opt-out
Hi Apollo team! I had a pilot study with 54 respondents and I got an interesting results. I have 8 decision situations with 3 alternatives and an opt-out option. I got the following results for the choices: Overview of choices for MNL model component : alt1 alt2 alt3 altnc Times available 432.00 432...
- 16 Aug 2021, 17:45
- Forum: Post-estimation analysis/use of results
- Topic: Delta method in random parameter models
- Replies: 14
- Views: 20163
Re: Delta method in random parameter models
Hi Stephane!
Thank you for the answer and help!
I will try to use the EM algorithm.
Best wishes,
David
Thank you for the answer and help!
I will try to use the EM algorithm.
Best wishes,
David
- 13 Aug 2021, 15:16
- Forum: Bug reports
- Topic: Error message "duplicated componentName" in Hybrid Choice Model using Bayesian approach
- Replies: 4
- Views: 17448
Re: Error message "duplicated componentName" in Hybrid Choice Model using Bayesian approach
Hi David!
Thank you very much!
It worked perfectly!
Best wishes,
David
Thank you very much!
It worked perfectly!
Best wishes,
David
- 13 Aug 2021, 15:15
- Forum: Post-estimation analysis/use of results
- Topic: Delta method in random parameter models
- Replies: 14
- Views: 20163
Re: Delta method in random parameter models
Hi Stephane, thank you for the answer! I get very different solution not only in latent class model with random parameters, but also in latent class with fix parameters. My code and the results are the following in preference space: ### Clear memory rm(list = ls()) ### Load Apollo library library(ap...