docs: def get_L_yXL(fname, y, x_in_X, L):
      '''
      compute the layer specificity, defined as:
      ::
      
          L_yXL = k_yXL / k_yX
      '''
      def _get_L_yXL_per_yXL(fname, x_in_X, X_index,
                                    y, layer):
          # Load data from json dictionary
          f = open(fname, 'r')
          data = json.load(f)
          f.close()
      
          
          # Get number of synapses
          if layer in [str(key) for key in data['data'][y]['syn_dict'].keys()]:
              #init variables
              k_yXL = 0
              k_yX = 0
              
              for x in x_in_X[X_index]:
                  p_yxL = data['data'][y]['syn_dict'][layer][x] / 100.
                  k_yL = data['data'][y]['syn_dict'][layer]['number of synapses per neuron']
                  k_yXL += p_yxL * k_yL
                  
              for l in [str(key) for key in data['data'][y]['syn_dict'].keys()]:
                  for x in x_in_X[X_index]:
                      p_yxL = data['data'][y]['syn_dict'][l][x] / 100.
                      k_yL = data['data'][y]['syn_dict'][l]['number of synapses per neuron']
                      k_yX +=  p_yxL * k_yL
              
              if k_yXL != 0.:
                  return k_yXL / k_yX
              else:
                  return 0.
          else:
              return 0.
  
  
      #init dict
      L_yXL = {}
  
      #iterate over postsynaptic cell types
      for y_value in y:
          #container
          data = np.zeros((len(L), len(x_in_X)))
          #iterate over lamina
          for i, Li in enumerate(L):
              #iterate over presynapse population inds
              for j in range(len(x_in_X)):
                  data[i][j]= _get_L_yXL_per_yXL(fname, x_in_X,
                                                            X_index=j,
                                                            y=y_value,
                                                            layer=Li)
          L_yXL[y_value] = data
  
      return L_yXL