I was wondering whether it is possible to calculate the Brier score for multinomial models in R?
library(nnet) data(iris) mlogit <- multinom(Species ~ ., data = iris)
and given the definition of the Brier score for multinomial model on Wikipedia. I do not believe I can compute the Brier score, because I lack the class probabilities of the non-realized classes for each observation right? Or am I missing something?