网友求助：
求助老师把“极品买点”中第一次出现B点时的副图指标公式改成选股公式，选出第一次出现买点或者说选股当天出现，谢谢。
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*0.999,'B'),colorred,linethick3;
DRAWTEXT(bu,LOW,'﹉'),Color208FFF,LINETHICK3;
DRAWTEXT(sel,HIGH,'﹉'),ColorFFFF00,LINETHICK3;
DRAWTEXT(sel,HIGH*1.008,'S'),colorffff00,linethick3;
STICKLINE(买线>=卖线,LOW,HIGH,1,0),colorred;
STICKLINE(买线>=卖线,CLOSE,OPEN,4.5,0),color0000aa;
STICKLINE(买线>=卖线,CLOSE,OPEN,4,0),color0000cc;
STICKLINE(买线>=卖线,CLOSE,OPEN,3,0),color0000cc;
STICKLINE(买线>=卖线,CLOSE,OPEN,2,0),color0000ee;
STICKLINE(买线<卖线,CLOSE,OPEN,4.5,0),coloraaaa00;
STICKLINE(买线<卖线,CLOSE,OPEN,4,0),colorbbbb00;
STICKLINE(买线<卖线,CLOSE,OPEN,3,0),colorcccc00;
STICKLINE(买线<卖线,CLOSE,OPEN,2,0),coloreeee00;
STICKLINE(买线<卖线,LOW,HIGH,1,0),colorffff00;
STICKLINE(CROSS(买线,卖线) OR CROSS(卖线,买线),OPEN,CLOSE,3,0),color00ffff;
指导线: EMA((EMA(CLOSE,4)+EMA(CLOSE,6)+EMA(CLOSE,12)+EMA(CLOSE,24))/4,2),linethick1,ColorFFffFF;
界: MA(CLOSE,27),linethick1,Color00FFFF;
DRAWTEXT(CROSS(指导线,界),界,'￣'),Colorffffff;
DRAWTEXT(CROSS(界,指导线),界,'￣'),Color00ffff;
RSV:=(CLOSE-LLV(LOW,9))/(HHV(HIGH,9)-LLV(LOW,9))*100;
K:=SMA(RSV,3,1);
D:=SMA(K,3,1);
J:=3*K-2*D;
G:=95;
解答如下：
买线:=EMA(C,2);
卖线:=EMA(SLOPE(C,13)*20+C,21);
RSV:=(CLOSE-LLV(LOW,9))/(HHV(HIGH,9)-LLV(LOW,9))*100;
K:=SMA(RSV,3,1);
D:=SMA(K,3,1);
xg:ISNULL(REFX(&CLOSE,1)) AND CROSS(买线,卖线) AND k>k[1] AND k[1]<40;
