和第二次底背离时间间隔30日内。第二次底背离时做选股

DIFF:=EMA(CLOSE,12)-EMA(CLOSE,26);
DEA:=EMA(DIFF,9);
A1:=BARSLAST(REF(CROSS(DIFF,DEA),1));
底背离:=REF(CLOSE,A1+1)>CLOSE AND DIFF>REF(DIFF,A1+1) AND CROSS(DIFF,DEA);
REF(BARSLAST(底背离),1)<=30 AND 底背离;