R/cutoffDA.R

In lbraglia/yapomif: Yet another package of misc functions

#' Calculate diagnostic accuracy measures for several cutoffs of a quantitative
#' marker.
#' 
#' Calculate diagnostic accuracy measures for several cutoffs of a quantitative
#' marker.
#' 
#' @param cutoffs Cutoffs considered
#' @param test Test
#' @param refstd Reference standard
#' @param round.dig Rounding digits
#' @param ... parameters passed to da
#' @return A data.frame for diagnostic accuracy studies.
#' @export
cutoffDA <- function(cutoffs = NULL, 
                     test = NULL,
                     refstd = NULL,
                     round.dig = 4,
                     ## parameters passed to da
                     ...
                     ){
  res <- list()
  
  for (tres in cutoffs)  {
    index <- which(cutoffs %in% tres)
    tmp <- 	da(test=(test > tres),  
                   refstd=refstd,  
                   round.dig=round.dig,
                   ...)[["stats"]]
    tmp$thresh <- tres
    res[[index]] <- tmp[c(5,1:4)]
  }
  
  do.call("rbind", res)
  
  ## Esempio chesi procalcitonina
  ## pct.gram <- roc(gram ~ pct, 
  ## direction="<", 
  ## data = db
  ## )
  ## ## Per verifiche a manina
  ## listRoc <- unclass(pct.gram)
  ## thresh.db <- da.at.cutoff(cutoffs=listRoc$thresholds,
  ## test=db$pct,
  ## refstd=db$gram)
  ## th.spl <- split(thresh.db, thresh.db$stat )
  ## ppv <- th.spl$PPV
  ## npv <- th.spl$NPV

}