主题：[原创]Keltner Channel

input:length(20,5,60,5),numatrs(1,1,3,1);
tprice:=(high+low+close)/3;
avgvalue:ma(tprice,length);
shiftvalue:=numatrs*ma(tr,length);
upperband:avgvalue+shiftvalue;
lowerband:avgvalue-shiftvalue;