def get_minmax(self):
        """Return min/max x/z coordinates of grid

        Returns
        -------
        x: [float, float]
            min, max values of grid dimensions in x direction (sideways)
        z: [float, float]
            min, max values of grid dimensions in z direction (downwards)

        """
        x_minmax = [np.min(self.grid['x']), np.max(self.grid['x'].max())]
        z_minmax = [np.min(self.grid['z']), np.max(self.grid['z'].max())]
        return x_minmax, z_minmax