编写要求：
DIF线与0轴角度大于30度选股
公式在线网解答：
DIFF:=EMA(CLOSE,12)/EMA(CLOSE,26)-1; DIF角度:=IF(DIFF>0,ATAN(DIFF/0.005/BARSLAST(CROSS(DIFF,0)))/3.142*180,0); DIF角度>=30;
