ApolloChoiceModelling forum

Hi Sara

you need to use / instead of \

It is also possible to do this via the menu in RStudio (tools-install packages) which will make it easier for you

Stephane

Hi apollo_prediction uses only the posterior means, so I would be very careful in using it in the situation where some of your marginal utility parameters are actually given by sums of multiple model parameters. Even if that wasn't the case, you should be very careful with using posterior means as t...

Hi Eduardo

you have included the same terms in both utilities, so the model is not identified. Apollo is telling you that b_female (the first parameter it tries) cannot change the log-likelihood as it influences both utilities in the same way.

Best wishes

Stephane

Hi 1. Your model is simply combining a number of different ordered logit models. You are not making any links between these components, so I wouldn't really refer to it as multivariate. If you want to create links between the models, you could incorporate a latent variable, for example. 2. The funct...

Hi Apollo relies on RSGHB for Bayesian estimation, and the posteriors are for each individual coefficient rather than an addition or other transformation involving multiple coefficients. With Normals, you could add up the posterior means, but would you really want to use a Normal for price anyway? W...

Hi Raffaele is this simply a case of you trying to run the whole file in one go? Try running it only to the estimate line, then it will prompt you to confirm whether you want to proceed with estimation - see the Estimate Model? (Y/N) prompt in your output. If you were running the whole file in one g...

Hi On point 1, what you could do is to use the alternative normalisation where you fix one zeta parameter to 1 per latent variable, but then estimate the standard deviation of the latent variable. So e.g., for the first LV, you could fix CAR_zeta_i6 to 1, but then estimate a standard deviation for P...

Peter

you found a bug - thanks! This was very specifically happening in the case of latent class models with continuous random coefficients in the class allocation component. I've just uploaded a new version of Apollo 0.1.1 on the website (www.ApolloChoiceModelling.com/code.html)

Stephane

Hi Toon

we've looked into this, and the kind of correction would be impractical to code in a general way (so it can be used with all models) and would also only appeal to a limited number of users of Apollo.

Best wishes

Stephane

Sara 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. The way to do this will depend on your oper...