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:
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Search found 4 matches

by user_8888
27 Sep 2022, 12:23
Forum: Errors during model validation and/or estimation.
Topic: Error MDCEV estimation - covariance matrix cannot be computed
Replies: 9
Views: 3423

Re: Error MDCEV estimation - covariance matrix cannot be computed

Dear Stephane,

it works now! Thanks!

I´ve increased again the iteration number and it does not produce NAs anamore.

Many thanks for the support.
by user_8888
19 Sep 2022, 10:24
Forum: Errors during model validation and/or estimation.
Topic: Error MDCEV estimation - covariance matrix cannot be computed
Replies: 9
Views: 3423

Re: Error MDCEV estimation - covariance matrix cannot be computed

Dear Stephane, I´ve used now 1.000 iterations. Unfortunately, I still get the warnings: 1: In log((inputs$continuousChoice[[j]]/inputs$gamma[[j]]) + ... : NaNs produced 2: In log(inputs$continuousChoice[[j]] + inputs$gamma[[j]]) : NaNs produced 3: In log((inputs$continuousChoice[[j]]/inputs$gamma[[j...
by user_8888
15 Sep 2022, 18:59
Forum: Errors during model validation and/or estimation.
Topic: Error MDCEV estimation - covariance matrix cannot be computed
Replies: 9
Views: 3423

Re: Error MDCEV estimation - covariance matrix cannot be computed

Hi, sorry that I didn´t provide the code to the issue - here is the model specification: # ################################################################# # #### DEFINE MODEL PARAMETERS #### # ################################################################# # ### Vector of parameters, including a...
by user_8888
15 Sep 2022, 14:52
Forum: Errors during model validation and/or estimation.
Topic: Error MDCEV estimation - covariance matrix cannot be computed
Replies: 9
Views: 3423

Error MDCEV estimation - covariance matrix cannot be computed

Dear all, We have an estimation problem with an MDCEV model (Error: cannot compute the covariance matrix) The data is from an experiment where people has to "configure" a residential location or a flat/ house choosng certain attributes (e.g. having a garden, flat size, location etc.). We h...