One Metropolis-Hastings sweep on alpha with Z integrated out
of the conditional. The proposal is a symmetric random walk in
delta = log(diff(alpha)) space; the acceptance ratio uses
the marginal ordinal-probit likelihood. Mixing of alpha
under this update is dramatically faster than the data-induced
Gibbs convention (Cowles 1996 reports ESS gains of an order of
magnitude on standard ordinal-probit benchmarks).
sample_alpha_cowles(alpha, Y_int, EZ, tau_prop, symmetric = FALSE)list with elements alpha, delta, accept
(logical).
numeric, current cutpoints with alpha[1] = 0,
length K-1.
integer matrix (or array) of ordinal categories coded
1..K, with NA for missing cells.
linear predictor at the dyad level, same shape as
Y_int.
numeric, RW proposal SD in delta space (will be adapted in burn-in by the caller).
logical, whether the network is symmetric (restricts the likelihood to upper-triangle cells so each dyad is counted once; variance 1, no precision rescaling).
Cassy Dorff, Shahryar Minhas, Tosin Salau