This function assess the model goodness of fit by calculate the
discrepancy measure T(bm(y), bm(Theta)) with following steps
(a) Generate T.obs based on the MCMC samples
(b) Generate T.rep based on the posterior distribution of the parameters
(c) Compare T.obs and T.rep, and calculate the P values.
Usage
BayesT(fit)
Value
Returns a dataframe with length equals to 2 that contains
observed and predict value