new_contents: from numba import jit, vectorize, float64
  import numpy as np
  
  
  
  @jit(nopython=True)
  def eep_fn(x, p5, p4, p3, p2, p1, p0, A, x0, tau, order=5):
      """Polynomial + exponential to approximate eep(age) for given track
      """
      if order < 5:
          p5 = 0
          if order < 4:
              p4 = 0
              if order < 3:
                  p3 = 0
                  if order < 2:
                      p2 = 0
  
      return p5*x**5 + p4*x**4 + p3*x**3 + p2*x**2 + p1*x + p0 + A*np.exp((x - x0)/tau)
  
  # @vectorize([float64(*[float64]*10)])
  # def eep_fn(x, p5, p4, p3, p2, p1, p0, A, x0, tau):
  #     """Polynomial + exponential to approximate eep(age) for given track
  #     """
  #     return p5*x**5 + p4*x**4 + p3*x**3 + p2*x**2 + p1*x + p0 + A*np.exp((x - x0)/tau)
  
  
  @jit(nopython=True)
  def eep_jac(x, p5, p4, p3, p2, p1, p0, A, x0, tau, order=5):
      """Jacobian of eep_fn
      """
      if order < 5:
          p5 = 0
          if order < 4:
              p4 = 0
              if order < 3:
                  p3 = 0
                  if order < 2:
                      p2 = 0
  
      n = len(x)
  
      result = np.empty((n, 9), dtype=float64)
      for i in range(n):
          xi = x[i]
          result[i, 0] = xi*xi*xi*xi*xi
          result[i, 1] = xi*xi*xi*xi
          result[i, 2] = xi*xi*xi
          result[i, 3] = xi*xi
          result[i, 4] = xi
          result[i, 5] = 0.
          result[i, 6] = np.exp((xi - x0)/tau)
          result[i, 7] = -1./tau * A * np.exp((xi - x0) / tau)
          result[i, 8] = -1./tau**2 * (xi - x0) * A * np.exp((xi - x0) / tau)
      return result
  
  def eep_fn_p0(ages, eeps, order=5):
      """seems to work well
      """
      m = eeps < 300
      p1, p0 = np.polyfit(ages[m], eeps[m], 1)
      return [0, 0, 0, 0, p1, p0, 1, ages.max()-0.3, 0.05]
  
  def fit_section_poly(age, eep, a, b, order=3):
      m = (a < eep) & (eep < b)
      if m.sum() < order + 1:
          raise ValueError
      return np.polyfit(age[m], eep[m], order)
  
subject: add file to repo