R/neImputeDS.R

In datashield/dsMediation: DataSHIELD Server side Mediation Analysis Functions

#'
#' @title Expand the dataset and impute nested counterfactual outcomes
#' @description This function is similar to R function \code{neImpute} from the 
#' \code{mmedflex} package.
#' @details The function 'neImpute' both expands the data along hypothetical exposure
#' values and imputes nested counterfactual outcomes.
#' @param object a string character, the name of an object used to select a method.
#' @param nMed an integer, the number of mediators to be considered jointly. For example,
#' if nMed = 2, not only the second predictor variable, but the two predictor
#' variables declared after the exposure variable are internally coded as mediators.
#' Correct specification of the (number of) mediators can easily be checked in the summary
#' output of the natural effect model object (returned by \code{ds.neModel} function), 
#' which lists the names of the exposure and all mediators. Default value of nMed is set
#' to 1.
#' @return a data frame of class c("data.frame", "expData", "impData") is assigned at
#' the server-side of each study.
#' @author Demetris Avraam, for DataSHIELD Development Team
#' @export
#'
neImputeDS <- function(object, nMed){
  
  object <- eval(parse(text=object), envir = parent.frame())

  out <- medflex::neImpute(object = object, nMed = nMed)
  
  return(out)
  
}