Nothing
#' @include randPar.R
NULL
###############################################
# --------------------------------------------#
# Class crPar #
# --------------------------------------------#
###############################################
# --------------------------------------------
# Function for validity check
# --------------------------------------------
# Validity check function for objects of the crPar class
#
# @inheritParams overview
#
# @return Returns a \code{TRUE}, if the settings of the object are valid.
validatecrPar <- function(object) {
errors <- character()
if(length(errors) == 0) TRUE else errors
}
# --------------------------------------------
# Class definition for crPar
# --------------------------------------------
# Randomization parameters generic
setClass("crPar", contains = "randPar", validity = validatecrPar)
# --------------------------------------------
# Constructor function for crPar
# --------------------------------------------
#' Representing Complete Randomization
#'
#' Represents the randomization procedure Complete Randomization.
#'
#' @details
#' Toss a fair coin \code{N} times in case \code{K=2} and assign the treatments according to the result of the coin. In case of \code{K>2}, replace the coin by a die with \code{K} sides.
#'
#' @family randomization procedures
#'
#' @inheritParams overview
#'
#' @return
#' \code{S4} object of the class \code{crPar}.
#'
#' @export
#'
#' @references
#' W. F. Rosenberger and J. M. Lachin (2002) \emph{Randomization in Clinical Trials}.
#' Wiley.
crPar <- function(N, K = 2, ratio = rep(1, K), groups = LETTERS[1:K]) {
new("crPar", N = N, K = K, ratio = ratio, groups = groups)
}
# --------------------------------------------
# Sampling algorithm for CR
# --------------------------------------------
# Complete Randomization
#
# This function implements a generalized version of Complete Randomization.
# In the original version Complete Randomization is equivalent to tossing
# a fair coin for a 1:1 allocation of subjects into two treatment groups.
# This version extends the original version to support more than two treatment
# groups and unequal allocation ratios.
#
# @inheritParams overview
#
# @return A vector with the allocation sequence for a clinical trial.
# It will contain the number {j-1} at position \code{i},
# when patient \code{i} is allocated to treatment \code{j} (\code{j=1,...,K}).
completeRand <- function(N, K = 2, ratio = rep(1, K)) {
sample(0:(K-1), size = N, prob = ratio/sum(ratio), replace = TRUE)
}
# --------------------------------------------
# Methods for crPar
# --------------------------------------------
#' @rdname generateAllSequences
setMethod("getAllSeq",
signature(obj = "crPar"),
function(obj) {
stopifnot(validObject(obj))
if(obj@K != 2 || !identical(obj@ratio, c(1,1))) {
stop("Only possible for K equals 2 and ratio corresponds to c(1,1).")
}
new("crSeq",
M = compltSet(obj),
N = N(obj),
K = K(obj),
ratio = obj@ratio,
groups = obj@groups)
}
)
#' @rdname generateRandomSequences
setMethod("genSeq",
signature(obj = "crPar", r = "numeric", seed = "numeric"),
function(obj, r, seed) {
set.seed(seed)
new("rCrSeq",
M = t(sapply(1:r, function(x) {
completeRand(N = N(obj), K = K(obj), ratio = ratio(obj))
})),
N = N(obj),
K = K(obj),
ratio = obj@ratio,
groups = obj@groups,
seed = seed)
}
)
#' @rdname generateRandomSequences
setMethod("genSeq",
signature(obj = "crPar", r = "missing", seed = "numeric"),
function(obj, r, seed) {
set.seed(seed)
new("rCrSeq",
M = t(completeRand(N = N(obj), K = K(obj), ratio = ratio(obj))),
N = N(obj),
K = K(obj),
ratio = obj@ratio,
groups = obj@groups,
seed = seed)
}
)
#' @rdname generateRandomSequences
setMethod("genSeq",
signature(obj = "crPar", r = "numeric", seed = "missing"),
function(obj, r, seed) {
seed <- sample(.Machine$integer.max, 1)
set.seed(seed)
new("rCrSeq",
M = t(sapply(1:r, function(x) {
completeRand(N = N(obj), K = K(obj), ratio = ratio(obj))
})),
N = N(obj),
K = K(obj),
ratio = obj@ratio,
groups = obj@groups,
seed = seed)
}
)
#' @rdname generateRandomSequences
setMethod("genSeq",
signature(obj = "crPar", r = "missing", seed = "missing"),
function(obj, r, seed) {
seed <- sample(.Machine$integer.max, 1)
set.seed(seed)
new("rCrSeq",
M = t(completeRand(N = N(obj), K = K(obj), ratio = ratio(obj))),
N = N(obj),
K = K(obj),
ratio = obj@ratio,
groups = obj@groups,
seed = seed)
}
)
#' @rdname getDesign
setMethod("getDesign",
signature(obj = "crPar"),
function(obj) {
"CR"
}
)
Any scripts or data that you put into this service are public.
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.