code: def rezero(self):
          
          dimension = self.vertices.shape[1]
          matrix = np.eye(dimension + 1)
          matrix[:dimension, dimension] = -self.vertices.min(axis=0)
          self.apply_transform(matrix)
          return matrix
docs: Translate so that every vertex is positive in the current
          mesh is positive.
  
          Returns
          -----------
          matrix : (dimension + 1, dimension + 1) float
            Homogenous transformation that was applied
            to the current Path object.