def __init__(self):
		'''创建表'''
		self.conn = sqlite3.connect("./items.db")
		if VERBOSE:
			print 'Database connection OPEN.'
		# Domain 表
		self.conn.execute(CTABLE_DOMAIN)
		# Website 表
		self.conn.execute(CTABLE_WEBSITE)
		# Rule 表 
		self.conn.execute(CTABLE_RULESETS)

		self.conn.commit()
		if VERBOSE:
			cur = self.conn.cursor()
			print 'Tables:',cur.execute("SELECT name FROM sqlite_master WHERE type = 'table'").fetchall()
def torque_fft(order, torque, ax=0):
    """plot torque harmonics"""
    unit = 'Nm'
    scale = 1
    if np.min(torque) < -9.9e3 or np.max(torque) > 9.9e3:
        scale = 1e-3
        unit = 'kNm'
    if ax == 0:
        ax = plt.gca()
    ax.set_title('Torque Harmonics / {}'.format(unit))
    ax.grid(True)

    try:
        bw = 2.5E-2*max(order)
        ax.bar(order, [scale*t for t in torque], width=bw, align='center')
        ax.set_xlim(left=-bw/2)
    except ValueError:  # empty sequence
        pass