orientation.py 文件源码

def _setup_normalized_vectors(self, normal_vector, north_vector):
        normal_vector, north_vector = _validate_unit_vectors(normal_vector,
                                                             north_vector)
        mylog.debug('Setting normalized vectors' + str(normal_vector)
                    + str(north_vector))
        # Now we set up our various vectors
        normal_vector /= np.sqrt(np.dot(normal_vector, normal_vector))
        if north_vector is None:
            vecs = np.identity(3)
            t = np.cross(normal_vector, vecs).sum(axis=1)
            ax = t.argmax()
            east_vector = np.cross(vecs[ax, :], normal_vector).ravel()
            # self.north_vector must remain None otherwise rotations about a fixed axis will break.
            # The north_vector calculated here will still be included in self.unit_vectors.
            north_vector = np.cross(normal_vector, east_vector).ravel()
        else:
            if self.steady_north or (np.dot(north_vector, normal_vector) != 0.0):
                north_vector = north_vector - np.dot(north_vector,normal_vector)*normal_vector
            east_vector = np.cross(north_vector, normal_vector).ravel()
        north_vector /= np.sqrt(np.dot(north_vector, north_vector))
        east_vector /= np.sqrt(np.dot(east_vector, east_vector))
        self.normal_vector = normal_vector
        self.north_vector = north_vector
        self.unit_vectors = YTArray([east_vector, north_vector, normal_vector], "")
        self.inv_mat = np.linalg.pinv(self.unit_vectors)