求大神帮忙看看哪里出问题了

日线收盘价在MA50上2天，以第二天收盘价平空开多；日线收盘价在MA50下2天，以第二天收盘价平多开空。代码如下：Params Numeric Length(50);Vars Series<Numeric> CloseD1; Series<Numeric> CloseD2; Series<Numeric>Length1; Events OnBar(ArrayRef<Integer> indexs) { CloseD1 = CloseD(0); CloseD2 = CloseD(1); Length1 =XAverage(Close,Length); PlotNumeric(\"EMA\",XAverage(Close, Length)); If(MarketPosition <>1 && CloseD1>Length1 && CloseD2>Length1) { Buy(0,Open); } If(MarketPosition <>-1 && CloseD1<Length1 && CloseD2<Length1) { SellShort(0,Open); } }