R/glance.dic.R

In njtierney/dsmcmc: tidy mcmc.list using data.table

#' Glance upon your dic samples to get the penalised deviance
#'
#' This provides a one-row dataframe (`data.table`) with information on the
#'  overall deviance, effective number of parameters (when `type` was pD) or
#'  optimism (when `type` was popt), and resulting penalised deviance.
#'
#' @param x a dic object generated by rjags::dic.samples
#' @param ... (optional) additional arguments to pass
#'
#' @return a one-row dataframe of summary information of the dic samples
#'
#' @author Sam Clifford, \email{sj.clifford@@gmail.com}
#'
#' @import data.table
#' @export
#' @examples
#' library(rjags)
#' example_jags_model$recompile()
#' model_dic <- dic.samples(example_jags_model, n.iter = 1000)
#' glance(model_dic)
glance.dic <- function(x, ...){

    dic_table <- with(x,
                      data.table::data.table(
                          deviance = as.numeric(deviance),
                          penalty = as.numeric(penalty),
                          type = as.character(type)
                      )
    )

    dic_return <- dic_table[ , lapply(.SD,
                                      sum),
                             .SDcols = c("deviance", "penalty") ,
                             by = type]

    dic_return[ , deviance_penalised := penalty + deviance  ]

    return(dic_return[])
}