Update attributes and latent class probabilities by sampling from full conditional distribution.
update_alpha(Amat, Q, ss, gs, Y, PIs, ALPHAS, delta0)A C by K matrix of latent classes.
A N by K matrix indicating which skills are required for which items.
A J vector of item slipping parameters.
A J vector of item guessing parameters.
A N by J matrix of observed responses.
A C vector of latent class probabilities.
A N by K matrix of latent attributes.
A J vector of Dirichlet prior parameters.
A N by K matrix of attributes and a C vector of class probabilities.