买卖线:=EMA(SLOPE(C,21)*21+C,42),COLORYELLOW,LINETHICK2;
DRAWCOLORLINE(买卖线>REF(买卖线,1),买卖线,COLORRED,COLORGREEN),LINETHICK2;
DRAWTEXT(CROSS(买卖线>REF(买卖线,1),0.5),买卖线,'买'),COLORRED;
DRAWTEXT(CROSS(买卖线<REF(买卖线,1),0.5),买卖线,'卖'),COLORGREEN;
CROSS(买卖线>REF(买卖线,1),0.5)||CROSS(买卖线<REF(买卖线,1),0.5),SOUND('A');