把图中出现买入红色箭头且K线为黄色时做预警公式

编写要求：

买线:=EMA(C,3);趋势下降线:=EMA(SLOPE(C,21)*20+C,42); 趋势线:趋势下降线,COLORGREEN,LINETHICK2;IF(C>趋势线 AND 趋势线 >=REF(趋势线 ,1), 趋势线 ,DRAWNULL),LINETHICK2,COLORRED;BU:=CROSS(买线,趋势下降线);SEL:=CROSS(趋势下降线,买线);DRAWICON(BU,L-0.1,1);DRAWICON(SEL,H+0.1,2);STICKLINE(买线>=趋势下降线,LOW,HIGH,0.0,1),COLORRED;STICKLINE(买线>=趋势下降线,CLOSE,OPEN,3,1),COLORRED;STICKLINE(买线<趋势下降线,LOW,HIGH,0.0,1),COLORGREEN;STICKLINE(买线<趋势下降线,CLOSE,OPEN,3,1),COLORGREEN;STICKLINE(BU,OPEN,CLOSE,3,0),COLORYELLOW;STICKLINE(SEL,OPEN,CLOSE,3,0),COLORBLUE;VAR21:=LLV(LOW,10);VAR31:=HHV(HIGH,25);阶段卖出:=3.2,COLORC6C600;动力线:=EMA((CLOSE-VAR21)/(VAR31-VAR21)*4,4),COLORYELLOW,LINETHICK2;清仓卖出:=3.5,COLORFF75FF;底部:=0.2,COLOR70DB93;关注:=0.5,COLORYELLOW;DRAWTEXT( FILTER(CROSS(动力线,关注),20),L*1,'底');DRAWTEXT( FILTER(CROSS(动力线,底部),20),L*1,'多');DRAWTEXT( FILTER(CROSS(阶段卖出,动力线),20),H*1,'顶');DRAWTEXT( FILTER(CROSS(清仓卖出,动力线),20),H*1,'空');DRAWTEXT_FIX(1,0.6,0,0,'操盘原则 黄多 兰空 红持股 绿持币 '),COLORYELLOW;

解答：

 买线:=EMA(C,3);