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 airgap(airgap, ax=0):
    """creates plot of flux density in airgap"""
    if ax == 0:
        ax = plt.gca()
    ax.set_title('Airgap Flux Density [T]')
    ax.plot(airgap['pos'], airgap['B'],
            label='Max {:4.2f} T'.format(max(airgap['B'])))
    ax.plot(airgap['pos'], airgap['B_fft'],
            label='Base Ampl {:4.2f} T'.format(airgap['Bamp']))
    ax.set_xlabel('Position/°')
    ax.legend()
    ax.grid(True)