N:=8;MID:=MA(C,20);VART1:=POW((C-MID),2);VART2:=MA(VART1,20);VART3:=SQRT(VART2);UPPER:=MID+2*VART3;LOWER:=MID-2*VART3;BOLL:=REF(MID,1);UB:=REF(UPPER,1);LB:=REF(LOWER,1);XG:(UB-LB)/BOLL (请自行调整N值。N越小,宽幅越小。)