code: def get_TRM_star(C, ptrms_vectors, start, end):
      
      TRM_star = numpy.zeros([len(ptrms_vectors), 3])
      TRM_star[0] = [0., 0., 0.]
      x_star = numpy.zeros(len(ptrms_vectors))
      for num, vec in enumerate(ptrms_vectors[1:]):
          TRM_star[num+1] = vec + C[num]
         # print 'vec', vec
         # print 'C', C[num]
      for num, trm in enumerate(TRM_star):
          x_star[num] = numpy.linalg.norm(trm)
      #print "x_star (should match corr_TRM / NRM)"
      #print x_star[start:end+1]
      return TRM_star[start:end+1], x_star[start:end+1]
docs: input: C, ptrms_vectors, start, end
      output: TRM_star, x_star (for delta_pal statistic)