def rezero(self):
        """
        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.
        """
        dimension = self.vertices.shape[1]
        matrix = np.eye(dimension + 1)
        matrix[:dimension, dimension] = -self.vertices.min(axis=0)
        self.apply_transform(matrix)
        return matrix
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.