empty tensor
netInput = np.empty([0, 4])
    netTarget = np.empty([0, 4])
    inputWidth = 2
    for step in range(data.shape.as_list()[-2]-frames_width-1):
        netInput = tf.concat([netInput, data[0, step:step + frames_width, :]], -2)
        target = tf.concat([target, data[0, step + frames_width + 1:step + frames_width + 2, :]], -2)
