Important: Read this before posting to this forum

  1. 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.
  2. 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
  3. Before asking a question on the forum, users are kindly requested to follow these steps:
    1. Check that the same issue has not already been addressed in the forum - there is a search tool.
    2. 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
    3. Check the frequently asked questions section on the Apollo website, which discusses some common issues/failures. Please see http://www.apollochoicemodelling.com/faq.html
    4. Make sure that R is using the latest official release of Apollo.
  4. If the above steps do not resolve the issue, then users should follow these steps when posting a question:
    1. provide full details on the issue, including the entire code and output, including any error messages
    2. 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.

Get predictions from the model with many alternatives

Report bugs or highlight issues with Apollo functions. At a minimum, please include the part of the output where you believe the bug is manifested. Ideally, please share your model file.
Post Reply
houman1372
Posts: 3
Joined: 26 Apr 2020, 17:41

Get predictions from the model with many alternatives

Post by houman1372 »

Hi
I have a question. After running the attached file I want to get predictions from the model. I use following commands:

predictions_base = apollo_prediction(model, apollo_probabilities, apollo_inputs)
summary(predictions_base[,3:ncol(predictions_base)])

But it causes this error:
Error in apollo_mnl(mnl_settings, functionality) :
Each element of "V" for model component "MNL" needs to be a scalar or a vector/matrix/cube with one row per observation in the "database"

I have used prediction before and it worked properly but when we use multiple data sources in this new way it comes to the error.
Is there any update on this?

Best,
Houman
Attachments
MNLDest.zip
(1.52 KiB) Downloaded 593 times
stephanehess
Site Admin
Posts: 974
Joined: 24 Apr 2020, 16:29

Re: Get predictions from the model with many alternatives

Post by stephanehess »

Hi Houman

thanks, this was a bug. This has been fixed in v.0.1.1 which you can download from the website (http://www.apollochoicemodelling.com/code.html)

Best wishes

Stephane
--------------------------------
Stephane Hess
www.stephanehess.me.uk
houman1372
Posts: 3
Joined: 26 Apr 2020, 17:41

Re: Get predictions from the model with many alternatives

Post by houman1372 »

Hi Stephane

There is the same problem in the apollo_outOfSample function. I would appreciate if you debug this error:

Error in apollo_mnl(mnl_settings, functionality) :
Each element of "V" for model component "MNL" needs to be a scalar or a vector/matrix/cube with one row per observation in the "database"

Regards,
Houman
dpalma
Posts: 190
Joined: 24 Apr 2020, 17:54

Re: Get predictions from the model with many alternatives

Post by dpalma »

Hi Houman,

Thank you for pointing this out. The problem has been resolved in the newly uploaded version in the webpage (new v0.1.1). You can download it from:
http://www.apollochoicemodelling.com/code.html

Best wishes
David
Post Reply