code: def area(poly):
      r
      a = 0.0
      n = len(poly)
  
      for i in range(n):
          a += poly[i][0] * poly[(i + 1) % n][1] - poly[(i + 1) % n][0] * poly[i][1]
  
      return abs(a) / 2.0
docs: r"""Find the area of a given polygon using the shoelace algorithm.
  
      Parameters
      ----------
      poly: (2, N) ndarray
          2-dimensional coordinates representing an ordered
          traversal around the edge a polygon.
  
      Returns
      -------
      area: float