"addData.MBdataDE" <-
function(x,N=NULL,n,IDs=NULL,M,W=NULL,design=NULL)
{
  isValid <- validObject(x)
  if(!is.null(N))
    {
      x@N <- N
      if(is.null(IDs))
        IDs <- rep(NA,N)
    }
  x@n <- x@n+n
  if(!is.null(IDs))
    x@IDs <- as.character(IDs)
  if(!is.matrix(M))
    M <- as.matrix(M)
  if(is.null(W))
    W <- matrix(1,x@N,n)
  else if(!is.matrix(W))
    W <- as.matrix(W)
  if(is.null(design))
    design <- as.matrix(rep(1,n))
  else if(!is.matrix(design))
    design <- as.matrix(design)

  if(length(x@M)==0)
    x@M <- M
  else
    {
      if(nrow(x@M) != nrow(M))
        stop("Number of genes of old/new @M data do not match")
      x@M <- cbind(x@M,M)
    }
  if(length(x@W)==0)
    x@W <- W
  else
    {
      if(nrow(x@W) != nrow(W))
        stop("Number of genes of old/new @W data do not match")
      x@W <- cbind(x@W,W)
    }
  if(length(x@design)==0)
    x@design <- design
  else
    {
      if(ncol(x@design) != ncol(design))
        stop("Number of coefficients of old/new @design matrices do not match")
      x@design <- rbind(x@design,design)
    }

  isValid <- validObject(x)
  return(x)
}