old_contents: import numpy as np
  from ..util import linalgebra
  
  def w(problem,X,type):
      
      if type == "ONE":
          return 1.
      if type == "EXP":
          len =  linalgebra.norm(X)
          return np.exp(- (len*len) / problem.neighbors.horizon)
      
      return 1.
new_contents: import numpy as np
  from ..util import linalgebra
  
  def w(problem,X,type):
      
      if type == "ONE":
          return 1.
      if type == "EXP":
          len =  linalgebra.norm(X)
          return np.exp(- (len*len) / problem.neighbors.horizon / problem.neighbors.horizon)
      if type == "NORM":
          return 1. / linalgebra.norm(X) 
      
      return 1.
subject: Add NORM as influence function