给这个“买卖线”主图出现“绝佳”时改个选股公式

编写要求：

买线:=EMA(C,2); 卖线:=EMA(SLOPE(C,21)*20+C,42); BU:=CROSS(买线,卖线); SEL:=CROSS(卖线,买线); DRAWTEXT(BU,LOW*0.98,'B买'),COLORYELLOW; DRAWTEXT(SEL,HIGH*1.008,'止损'),COLORGREEN; DRAWTEXT(CROSS(ZIG(3,8),REF(ZIG(3,8),1)),LOW*0.978,'★绝佳') ,LINETHICK2,COLORRED; {STICKLINE(买线>=卖线,LOW,HIGH,0.0,1),COLORRED; STICKLINE(买线>=卖线,CLOSE,OPEN,1,0),COLORLIRED;} STICKLINE(买线<卖线,CLOSE,OPEN,1,0),COLORGRAY; {STICKLINE(买线<卖线,LOW,HIGH,0.0,0)COLORGRAY;} STICKLINE(CROSS(买线,卖线),OPEN,CLOSE,1,0),COLORYELLOW; STICKLINE(CROSS(卖线,买线),OPEN,CLOSE,1,0),COLORBLUE; DRAWTEXT(CROSS(REF(ZIG(3,10),1),ZIG(3,10)),HIGH*1.02,'S卖'),COLORGREEN; STICKLINE(CROSS(REF(ZIG(3,10),1),ZIG(3,10)),OPEN,CLOSE,1,0),COLORBLUE; A25:=EMA(EMA(EMA(CLOSE, 3), 3), 3); 多方:((A25-REF(A25,1))+A25)COLORMAGENTA,LINETHICK2; 空方:MA(多方, 4)COLORCYAN,LINETHICK1; K2:=BACKSET(多方

解答：

?CROSS(ZIG(3,8),REF(ZIG(3,8),1));