编写要求：
MACD零上二次金叉预警公式
股票网解答：
DIFF:=EMA(CLOSE,12)-EMA(CLOSE,26);
DEA:=EMA(DIFF,9);
MACD:=2*(DIFF-DEA),COLORSTICK;
JCCOUNT:=COUNT(CROSS(DIFF,DEA),BARSLAST(DEA>=0));
金叉:=CROSS(DIFF,DEA) AND DEA>0 AND COUNT(JCCOUNT=1,21)=1;
二金叉:CROSS(DIFF,DEA) AND DEA>0 AND COUNT(JCCOUNT=2,21)=1;