code: def cdf(arr, pos=None):
      '''
      Return the cumulative density function of a given array or
      its intensity at a given position (0-1)
      '''
  
      r = (arr.min(), arr.max())
      hist, bin_edges = np.histogram(arr, bins=2 * int(r[1] - r[0]), range=r)
      hist = np.asfarray(hist) / hist.sum()
      cdf = np.cumsum(hist)
      if pos is None:
          return cdf
      i = np.argmax(cdf > pos)
      return bin_edges[if cdf(arr, pos=None):
      '''
      Return the cumulative density function of a given array or
      its intensity at a given position (0-1)
      '''
  
      r = (arr.min(), arr.max())
      hist, bin_edges = np.histogram(arr, bins=2 * int(r[1] - r[0]), range=r)
      hist = np.asfarray(hist) / hist.sum()
      cdf = np.cumsum(hist)
      if pos is None:
          return cdf
      i = np.argmax(cdf > pos)
      return bin_edges[i]
docs: Return the cumulative density function of a given array or
      its intensity at a given position (0-1)