def strike_dip(self, degrees=True):
        """
        Computes strike and dip from a normal vector.
        Results are usually the same as LLSQ
        in strike (to a few decimal places) and close in dip.
        Sometimes, dips are greater by as much as 45 degrees,
        reflecting inclusion of errors in x-y plane.
        """
        n = self.axes[2]
        r = N.linalg.norm(n)
        strike = N.degrees(N.arctan2(n[0],n[1]))-90
        dip = N.degrees(N.arccos(n[2]/r))

        # Since PCA errors are not pinned to the XYZ plane,
        # we need to make sure our results are in the
        # right quadrant.
        if dip > 90:
            dip = 180 - dip
            strike += 180

        # Proper azimuth notation
        if strike < 0:
            strike += 360

        return strike, dip