pdf_normalize_2d Subroutine

subroutine pdf_normalize_2d(self)
  type(pdf_kernel_2d) :: self
  if(.not.self%status)stop "PDF_NORMALIZE: PDF not allocated"
  if(.not.self%rescale)self%pdf = self%pdf/self%Ndata
  self%rescale = .true.
  self%pdf = self%pdf/sum(self%pdf)/product(self%dx)
end subroutine pdf_normalize_2d