R/sampler.R

In davharris/mistnet: Stochastic Neural Networks

#' Samplers
#' 
#' Samplers produce Monte Carlo samples for \code{\link{network}} objects.
#' @rdname sampler
sampler = setRefClass(
  Class = "sampler",
  fields = list(),
  methods = list(
    sample = function(...){
      stop("no sampling method defined for this sampler")
    },
    log_density = function(){
      stop("no log-density function defined for this sampler")
    }
  )
)

#' @export gaussian.sampler
#' @exportClass gaussian.sampler
#' @rdname sampler
gaussian.sampler = setRefClass(
  Class = "gaussian.sampler",
  fields = list(
    ncol = "integer",
    sd = "numeric"
  ),
  methods = list(
    sample = function(nrow){
      out = rnorm(nrow * ncol, sd = sd)
      dim(out) = c(nrow, ncol)
      
      out
    },
    log_density = function(x){
      dnorm(x, mean = 0, sd = sd, log = TRUE)
    }
  ),
  contains = "sampler"
)