编写要求：
请老师改个选股公式：最近3天内MACD金叉，并且出现“买”（金叉和买可以是同一天出现或相继出现），谢谢！
DIFF:EMA(CLOSE,7) - EMA(CLOSE,19);
DEA:EMA(DIFF,9);
MACD:2*(DIFF-DEA),COLORSTICK;
A1:=BARSLAST(REF(CROSS(DIFF,DEA),1));
B1:=REF(C,A1+1)>C AND REF(DIFF,A1+1)C AND REF("KDJ.K"(9,3,3),A2+1)<"KDJ.K"(9,3,3) AND CROSS("KDJ.K"(9,3,3),"KDJ.D"(9,3,3));
A3:=BARSLAST(REF(CROSS("RSI.RSI1"(6,12,24),"RSI.RSI2"(6,12,24)),1));
B3:=REF(C,A3+1)>C AND REF("RSI.RSI1"(6,12,24),A3+1)<"RSI.RSI1"(6,12,24) AND CROSS("RSI.RSI1"(6,12,24),"RSI.RSI2"(6,12,24));
C1:=BARSLAST(REF(CROSS(DEA,DIFF),1));
D1:=REF(C,C1+1)DIFF AND CROSS(DEA,DIFF);
C2:=BARSLAST(REF(CROSS("KDJ.D"(9,3,3),"KDJ.K"(9,3,3)),1));
D2:=REF(C,C2+1)"KDJ.K"(9,3,3) AND CROSS("KDJ.D"(9,3,3),"KDJ.K"(9,3,3));
C3:=BARSLAST(REF(CROSS("RSI.RSI2"(6,12,24),"RSI.RSI1"(6,12,24)),1));
D3:=REF(C,C3+1)"RSI.RSI1"(6,12,24) AND CROSS("RSI.RSI2"(6,12,24),"RSI.RSI1"(6,12,24));
M底背:IF(B1>0,-0.1,0),COLORRED,POINTDOT;
K底背:IF(B2>0,-0.1,0),COLORFF00FF,POINTDOT;
R底背:IF(B3>0,-0.1,0),COLORYELLOW,POINTDOT;
MACD顶背:=IF(D1>0,0.1,0),COLOR00FF00,POINTDOT;
KDJ顶背:=IF(D2>0,0.1,0),COLORFFCC66,POINTDOT;
RSI顶背:=IF(D3>0,0.1,0),COLORWHITE,POINTDOT;
STICKLINE(B1>0,-0.1,0,2,0),COLORRED;
STICKLINE(B2>0,-0.1,0,2,0),COLORFF00FF;
STICKLINE(B3>0,-0.1,0,2,0),COLORYELLOW;
STICKLINE(D1>0,0.1,0,2,0),COLOR00FF00;
STICKLINE(D2>0,0.1,0,2,0),COLORFFCC66;
STICKLINE(D3>0,0.1,0,2,0),COLORWHITE;
STICKLINE(MACD>REF(MACD,1) AND MACD>0,0,MACD,0,0),COLORRED;
STICKLINE(MACD<=REF(MACD,1) AND MACD>0,0,MACD,0,0),COLORYELLOW;
STICKLINE(MACD=REF(MACD,1) AND MACD<0,0,MACD,0,0),COLORMAGENTA;
STICKLINE(C>0,0,0,50,1),COLORBLUE;
强:IF(DIFF>MA(DIFF,2),DIFF,DRAWNULL),COLORRED,LINETHICK2;
弱:IF(DEA>MA(DEA,2),DEA,DRAWNULL),COLORMAGENTA,LINETHICK2;
DRAWICON(CROSS(DIFF,DEA),DEA,26);
DRAWICON(CROSS(DEA,DIFF),DEA,27);
A:=REF(DIFF,1)REF(DIFF,1);
B:=REF(DIFF,1)>REF(DIFF,2) AND REF(DIFF,2)>REF(DIFF,3) AND DIFF=REF(M3,1),M3,REF(M3,1),3,1),COLORYELLOW;
STICKLINE(M3
解答：
?DIFF:=EMA(CLOSE,7) - EMA(CLOSE,19);
DEA:=EMA(DIFF,9);
