This is a helper function for choice_probabilities and computes
the probit choice probabilities for a single choice situation with J
alternatives.
compute_choice_probabilities(X, alternatives, parameter, ordered = FALSE)A probability vector of length length(alternatives).
A matrix of covariates with J rows and P_f + P_r columns, where
the first P_f columns are connected to fixed coefficients and the last
P_r columns are connected to random coefficients.
A vector with unique integers from 1 to J, indicating the
alternatives for which choice probabilities are to be computed.
An object of class RprobitB_parameter.
[logical(1)]
If TRUE, the choice set alternatives is assumed to be ordered
from worst to best.