R/transformationfunctions.R

In Sondre91/STGARCH: STGARCH

#' Functions for transforming arrays
#'
#' Transforms an array from 3D to 2D by stacking column vectors
#' @param X 3D array
#' @return 2D array

tilVektor<-function(X){
  d<-dim(X)
  M<-matrix(NA_real_,nrow=d[1]*d[2], ncol=d[3])
  for(t in 1:d[3]){
    M[,t]<-as.vector(t(X[,,t]))
  }
  M
}
#' Functions for transforming arrays
#'
#' Transforms an array from 4D to 3D by stacking column vectors
#' @param X 4D array
#' @return 3D array
tilArray<-function(X){
  d<-dim(X)
  M<-array(NA_real_, dim=c(d[1]*d[2],d[3],d[4]))
  for(i in 1:d[4]){
    for(t in 1:d[3]){
      M[,t,i]<-as.vector(t(X[,,t,i]))
    }
    M
  }
}
#' Functions for transforming arrays
#'
#' Transforms an array from 3D to 2D by stacking column vectors
#' @param X  3D array
#' @return 2D array
stacker<-function(X){
  d<-dim(X)
  M<-matrix(NA_real_, nrow=d[1]*d[3], ncol=d[2])
  for(i in 1:d[3]-1){
    M[(1:d[1])+i*d[1],]<-X[,,i+1]
  }
  return(M)
}