隐含波动率

Vars Global Integer id(0); Global Bool subFlag(False);Events OnReady() { if(!subFlag) { id = SubscribeBar(RelativeSymbol, \"1d\", BeginDateTime); subFlag = True; } } OnBar(ArrayRef<Integer> indexs) { Numeric volty = Volatility(data[id].Close); Print(\"Option_ImVolatility:\" + Text(Option_ImVolatility(Close, data[id].Close, StrikePrice, TradingDayLeft, 5, volty, 2, OptionType, 240))); }在中证1000认沽合约的图表上载入这个策略，不显示具体数值，控制台显示是N/A,请问怎么结局