R/opchar.R

In mjg211/OptGS: Optimal and Near-optimal Group-sequential Designs for Clinical Trials with Continuous Outcomes

#' Calculate the operating characteristics of a group-sequential clinical trial
#' design for a normally distributed primary outcome
#'
#' \code{opchar()} analytically calculates the operating characteristics of a
#' group-sequential clinical trial.
#'
#' @param des An object of class \code{"OptGS_des"}, as returned by
#' \code{\link{des_gs}}, \code{\link{des_nearopt}}, \code{\link{des_opt}}, or
#' \code{\link{build}}. Defaults to \code{des_gs()}.
#' @param tau A \code{\link{numeric}} \code{\link{vector}} indicating the values
#' of \ifelse{html}{\out{<i>&tau;</i>}}{\eqn{\tau}} to perform calculations for.
#' Defaults to \code{seq(-des$delta, 2*des$delta, length.out = 100)}.
#' @param summary A \code{\link{logical}} variable indicating whether a summary
#' of the function's progress should be printed to the console. Defaults to
#' \code{FALSE}.
#' @return A \code{\link{list}} with additional class \code{"OptGS_opchar"}. It
#' will contain each of the input variables (subject to internal modification),
#' along with the following elements:
#' \itemize{
#' \item \code{opchar}: A \code{\link{tibble}} giving the calculated operating
#' characteristics.
#' }
#' @examples
#' # Calculations for the default parameters
#' opchar     <- opchar()
#' @seealso \code{\link{des_gs}}, \code{\link{des_nearopt}},
#' \code{\link{des_opt}}, \code{\link{build}}, \code{\link{est}},
#' \code{\link{sim}}, \code{\link{plot.OptGS_opchar}}
#' @export
opchar <- function(des = OptGS::des_gs(),
                   tau = seq(-des$delta, 2*des$delta, length.out = 100),
                   summary = FALSE) {

  ##### Check input variables ##################################################

  check_OptGS_des(des, "des")
  check_tau(tau)
  check_logical(summary, "summary")

  ##### Print summary ##########################################################

  if (summary) {
    #summary_opchar(des, tau)
    message("")
  }

  ##### Perform main computations ##############################################

  opchar        <- opchar_int(tau, des$e, des$f, sqrt(des$I), des$CovZ, des$n)

  ##### Output #################################################################

  output        <- list(des     = des,
                        opchar  = opchar,
                        summary = summary,
                        tau     = tau)
  class(output) <- c(class(output), "OptGS_opchar")
  output

}