R/blots.R

In mice: Multivariate Imputation by Chained Equations

#' Creates a \code{blots} argument
#'
#' This helper function creates a valid \code{blots} object. The
#' \code{blots} object is an argument to the \code{mice} function.
#' The name \code{blots} is a contraction of blocks-dots.
#' Through \code{blots}, the user can specify any additional
#' arguments that are specifically passed down to the lowest level
#' imputation function.
#' @param data A \code{data.frame} with the source data
#' @param blocks An optional specification for blocks of variables in
#' the rows. The default assigns each variable in its own block.
#' @return A matrix
#' @seealso \code{\link{make.blocks}}
#' @examples
#' make.predictorMatrix(nhanes)
#' make.blots(nhanes, blocks = name.blocks(c("age", "hyp"), "xxx"))
#' @export
make.blots <- function(data, blocks = make.blocks(data)) {
  data <- check.dataform(data)
  blots <- vector("list", length(blocks))
  for (i in seq_along(blots)) blots[[i]] <- alist()
  names(blots) <- names(blocks)
  blots
}

check.blots <- function(blots, data, blocks = NULL) {
  data <- check.dataform(data)

  if (is.null(blots)) {
    return(make.blots(data, blocks))
  }

  blots <- as.list(blots)
  for (i in seq_along(blots)) blots[[i]] <- as.list(blots[[i]])

  if (length(blots) == length(blocks) && is.null(names(blots))) {
    names(blots) <- names(blocks)
  }
  blots
}