R/utility_useknd.R

In kisungyou/SHT: Statistical Hypothesis Testing Toolbox

#' Apply k-sample tests for two multivariate samples
#' 
#' Any \eqn{k}-sample method implies that it can be used for 
#' a special case of \eqn{k=2}. \code{useknd} lets any \eqn{k}-sample tests 
#' provided in this package be used with two multivariate samples \eqn{X} and \eqn{Y}.
#' 
#' @param X an \eqn{(n_x \times p)} data matrix of 1st sample.
#' @param Y an \eqn{(n_y \times p)} data matrix of 2nd sample.
#' @param test.name character string for the name of k-sample test to be used.
#' @param ... extra arguments passed onto the function \code{test.name}.
#' 
#' @return a (list) object of \code{S3} class \code{htest} containing: \describe{
#' \item{statistic}{a test statistic.}
#' \item{p.value}{\eqn{p}-value under \eqn{H_0}.}
#' \item{alternative}{alternative hypothesis.}
#' \item{method}{name of the test.}
#' \item{data.name}{name(s) of provided sample data.}
#' }
#' 
#' @examples
#' \donttest{
#' ## use 'covk.2007Schott' for two-sample covariance testing
#' ## empirical Type 1 error 
#' niter   = 1000
#' counter = rep(0,niter)  # record p-values
#' for (i in 1:niter){
#'   X = matrix(rnorm(50*5), ncol=10)
#'   Y = matrix(rnorm(50*5), ncol=10)
#'   
#'   counter[i] = ifelse(useknd(X,Y,"covk.2007Schott")$p.value < 0.05, 1, 0)
#' }
#' 
#' ## print the result
#' cat(paste("\n* Example for 'covk.2007Schott'\n","*\n",
#' "* number of rejections   : ", sum(counter),"\n",
#' "* total number of trials : ", niter,"\n",
#' "* empirical Type 1 error : ",round(sum(counter/niter),5),"\n",sep=""))
#' }
#' 
#' @concept utility
#' @export
useknd <- function(X, Y, test.name, ...){
  ##############################################################
  # PREPROCESSING
  check_nd(X)
  check_nd(Y)
  if (!is.character(test.name)){
    stop("* useknd : provide your 'test.name' as a valid character string.")
  }
  mydata = list()  # wrap the data
  mydata[[1]] = X
  mydata[[2]] = Y
  
  ##############################################################
  # RUN
  funcget = get(test.name)
  tmpout = funcget(mydata,...)
  
  ##############################################################
  # RETURN
  DNAME = paste(deparse(substitute(X))," and ",deparse(substitute(X)),sep="") # borrowed from HDtest
  tmpout$data.name = DNAME
  return(tmpout)
}