text: Title: [ENH] Empirical CDF calculation
  Body: Because @ericmjl & I keep copypasta'ing it across all my notebooks
  
  ```python
  def calc_single_ecdf(data):
      """Compute the Empirical Cumulative Distribution Function for an Array."""
      # Number of points n
      n = len(data)
  
      # x data for the CDF 
      x = np.sort(data)
  
      # y data for the CDF
      y = np.arange(1, n + 1 ) / n
  
      return x, y
  ```