polymirt fits an unconditional (exploratory)
  full-information maximum-likelihood factor analysis model
  to dichotomous and polytomous data under the item
  response theory paradigm using Cai's (2010)
  Metropolis-Hastings Robbins-Monro algorithm. The function
  is currently depreciated and instead should be run by
  using the confmirt function.polymirt(...)confmirt estimation engineexpand.table, key2binary,
  confmirt, itemplot