R/ordinal-mean-diff.R

In bayesMeanScale: Bayesian Post-Estimation on the Mean Scale

ordinalMeanDiffF <- function(pred_start, pred_end, model_data, marg_list, at, at_means, i){

  if(!is.null(at) & at_means==F){

    atVars    <- names(expand.grid(at))
    groupVars <- c(atVars, "draw")
    
    predDiff <- (pred_start[, .SD, .SDcols=!groupVars] - pred_end[, .SD, .SDcols=!groupVars]) %>%
      cbind(subset(pred_start, select=groupVars)) %>%
      .[, lapply(.SD, mean), by=groupVars, .SDcols=!groupVars] %>%
      data.table::melt(id.vars       = groupVars,
                       variable.name = 'outcome',
                       value.name    = 'diff') %>%
      .[, `:=` (comparison  = paste0(marg_list$start[[i]], " vs. ", marg_list$end[[i]]),
                marg_effect = marg_list$marg[[i]])] %>%
      .[, .SD, .SDcols=!"draw"]

  }
  
  if(is.null(at) & at_means==F){
    
    predDiff <- (pred_start[, .SD, .SDcols=!"draw"] - pred_end[, .SD, .SDcols=!"draw"]) %>%
      cbind(subset(pred_start, select=draw)) %>%
      .[, lapply(.SD, mean), by="draw", .SDcols=!"draw"] %>%
      data.table::melt(id.vars       = "draw",
                       variable.name = 'outcome',
                       value.name    = 'diff') %>%
      .[, `:=` (comparison  = paste0(marg_list$start[[i]], " vs. ", marg_list$end[[i]]),
                marg_effect = marg_list$marg[[i]])] %>%
      .[, .SD, .SDcols=!"draw"]

  }
  
  if(!is.null(at) & at_means==T){
    
    atVars    <- names(expand.grid(at))
    groupVars <- c(atVars, "draw")
    
    predDiff <- (pred_start[, .SD, .SDcols=!groupVars] - pred_end[, .SD, .SDcols=!groupVars]) %>%
      cbind(subset(pred_start, select=groupVars)) %>%
      data.table::melt(id.vars       = groupVars,
                       variable.name = 'outcome',
                       value.name    = 'diff') %>%
      .[, `:=` (comparison  = paste0(marg_list$start[[i]], " vs. ", marg_list$end[[i]]),
                marg_effect = marg_list$marg[[i]])] %>%
      .[, .SD, .SDcols=!"draw"]
    
  }
  
  if(is.null(at) & at_means==T){
    
    predDiff <- (pred_start[, .SD, .SDcols=!"draw"] - pred_end[, .SD, .SDcols=!"draw"]) %>%
      cbind(subset(pred_start, select=draw)) %>%
      data.table::melt(id.vars       = "draw",
                       variable.name = 'outcome',
                       value.name    = 'diff') %>%
      .[, `:=` (comparison  = paste0(marg_list$start[[i]], " vs. ", marg_list$end[[i]]),
                marg_effect = marg_list$marg[[i]])] %>%
      .[, .SD, .SDcols=!"draw"]
    
  }
  
  return(predDiff)

}