通达信布林开口选股指标(源码)

N:=20;
BOLL:=MA(CLOSE,N);
UPPER:=BOLL+2*STD(CLOSE,N);
LOWER:=BOLL-2*STD(CLOSE,N);
DD:=UPPER-LOWER;
XG:CROSS(0.5,DD=LLV(DD,30));