code: def sortedbyAge(self):
  		'''
  		Sorting the pop. base of the age
  		'''
  		ageAll = numpy.zeros(self.length)
  		for i in range(self.length):
  			ageAll[i] = self.Ind[i].age
  		ageSorted = ageAll.argsort()
  		return ageSorted[::-1]