上下通道，比较直观点
 
INPUT:N(240,0,999);
 hh:=hhv(h,N);
 hhh:=h;
 aa:=BARSLAST(h=hh[datacount]);
 ba:datacount-aa,LINETHICK0;
 ja:=1;
 tm1:=999999;
 for i1=ba[datacount]+1 to datacount do begin
 k1:=(hh[datacount]-hhh[i1])/ja;
 if k1<tm1 then begin
 tm1:=k1;
 ts1:=ja;
 end;
 ja:=ja+1;
 end;
 A1:LINEVALUE(h=hh[datacount] and aa=0,h,BARPOS=datacount-aa[datacount]+ts1,h,0,0),colorffff54;
 cha:=hhv(abs(l-a1),aa);
 A2:a1-cha[datacount],colorffff54;
 AI:a1-cha[datacount]/2,colorffff54,LINEDASH;
 ll:=llv(l,N);
 lll:=l;
 a3:=BARSLAST(l=ll[datacount]);
 b3:=datacount-a3;
 j3:=1;
 tm3:=999999;
 for i3=b3[datacount]+1 to datacount do begin
 k3:=(lll[i3]-ll[datacount])/j3;
 if k3<tm3 then begin
 tm3:=k3;
 ts3:=j3;
 end;
 j3:=j3+1;
 end;
 B1:LINEVALUE(l=ll[datacount] and a3=0,l,BARPOS=datacount-a3[datacount]+ts3,l,0,0),color5454ff;
 chb:=hhv(abs(h-b1),a3);
 b2:b1+chb[datacount],color5454ff;
 bi:b1+chb[datacount]/2,color5454ff,LINEDASH;