old_contents: """This module define the Structure object"""
  
  
  class Fourier(object):
      __radiation_type = ["neutrons", "xray", "electrons"]
  
      def __init__(self):
          self.structure = None
          self.radiation = 'neutrons'
          self.wavelenght = 1.54
          self.lots = None
          self.average = 0.0
          self.na = 101
          self.no = 101
          self.ll = [0.0, 0.0, 0.0]
          self.lr = [2.0, 0.0, 0.0]
          self.ul = [0.0, 2.0, 0.0]
  
      def calculate(self):
          # returns Data object
          pass
  
new_contents: """This module define the Structure object"""
  import numpy as np
  
  
  class Fourier(object):
      __radiation_type = ["neutrons", "xray", "electrons"]
  
      def __init__(self):
          self.structure = None
          self.radiation = 'neutrons'
          self.wavelenght = 1.54
          self.lots = None
          self.average = 0.0
          self.na = 101
          self.no = 101
          self.ll = np.array([0.0, 0.0, 0.0])
          self.lr = np.array([2.0, 0.0, 0.0])
          self.ul = np.array([0.0, 2.0, 0.0])
  
      def calculate(self):
          """Returns a Data object"""
          output_array = np.zeros([self.na, self.no], dtype=np.complex)
          vector1_step = (self.lr - self.ll)/(self.na-1)
          vector2_step = (self.ul - self.ll)/(self.no-1)
          kx = np.zeros([self.na, self.no])
          ky = np.zeros([self.na, self.no])
          kz = np.zeros([self.na, self.no])
          for x in range(self.na):
              for y in range(self.no):
                  v = self.ll + x*vector1_step + y*vector2_step
                  kx[x, y] = v[0]
                  ky[x, y] = v[1]
                  kz[x, y] = v[2]
          kx *= (2*np.pi)
          ky *= (2*np.pi)
          kz *= (2*np.pi)
          for atom in self.structure.get_scaled_positions():
              dot = kx*atom[0] + ky*atom[1] + kz*atom[2]
              output_array += np.exp(dot*1j)
          results = np.real(output_array*np.conj(output_array))
          return results
  
      def calculate_fast(self):
          """Returns a Data object"""
          output_array = np.zeros([self.na, self.no], dtype=np.complex)
          kx, ky, kz = calc_k_grid(self.ll, self.lr, self.ul, self.na, self.no)
          kx *= (2*np.pi)
          ky *= (2*np.pi)
          kz *= (2*np.pi)
          for atom in self.structure.get_scaled_positions():
              dotx = np.exp(kx*atom[0]*1j)
              doty = np.exp(ky*atom[1]*1j)
              dotz = np.exp(kz*atom[2]*1j)
              sumexp = dotx * doty * dotz
              output_array += sumexp
          results = np.real(output_array*np.conj(output_array))
          return results
  
  
  def calc_k_grid(ll, lr, ul, na, no):
      va = lr - ll
      vo = ul - ll
      vector1_step = (lr - ll)/(na-1)
      vector2_step = (ul - ll)/(no-1)
      kx_bina, kx_bino = get_bin_number(va, vo, na, no, 0)
      ky_bina, ky_bino = get_bin_number(va, vo, na, no, 1)
      kz_bina, kz_bino = get_bin_number(va, vo, na, no, 2)
      kx = np.zeros([kx_bina, kx_bino])
      ky = np.zeros([ky_bina, ky_bino])
      kz = np.zeros([kz_bina, kz_bino])
      for x in range(kx_bina):
          for y in range(kx_bino):
              v = ll + x*vector1_step + y*vector2_step
              kx[x, y] = v[0]
      for x in range(ky_bina):
          for y in range(ky_bino):
              v = ll + x*vector1_step + y*vector2_step
              ky[x, y] = v[1]
      for x in range(kz_bina):
          for y in range(kz_bino):
              v = ll + x*vector1_step + y*vector2_step
              kz[x, y] = v[2]
      return kx, ky, kz
  
  
  def get_bin_number(va, vo, na, no, index):
      if va[index] == 0:
          binx = 1
      else:
          binx = na
      if vo[index] == 0:
          biny = 1
      else:
          biny = no
      return binx, biny
  
subject: Add working fourier calculations