指标请写成模型

建立一个交易公式，然后把下列代码复制进去

diff:ema(close,28)-ema(close,199);
dea:ema(diff,9);
stickline(diff<=dea,diff,dea,colorgreen,0);
stickline(diff>dea,diff,dea,colorred,0);
drawtext(cross(diff,dea),close,'多');
drawtext(cross(dea,diff),close,'空');
if cross(diff,dea) then begin
 sellshort(1,0,limitr,close);
 buy(holding=0,1,limitr,close);
end

if cross(dea,diff) then begin
 sell(1,0,limitr,close);
 buyshort(holding=0,1,limitr,close);
end

diff:ema(close,28)-ema(close,199);
dea:ema(diff,9);
stickline(diff<=dea,diff,dea,colorgreen,0);
stickline(diff>dea,diff,dea,colorred,0);
drawtext(cross(diff,dea),close,'多');
drawtext(cross(dea,diff),close,'空');
sellshort(cross(diff,dea),0,limitr,close);
buy(ref(cross(diff,dea),1) and holding=0,1,limitr,close);

sell(cross(dea,diff),0,limitr,close);
buyshort(ref(cross(dea,diff),1) and holding=0,1,limitr,close);