如何判断Boll Band发散和收敛

 

比如用30分钟图,如何取出前后的数值再进行比较

没有思路,谁人指点一下,谢谢

 

StdDev大于前值发散,小于前值收敛

'Bollinger Bands, BB'

Math:

StdDev = SQRT(SUM[(CLOSE — SMA(CLOSE, N))^2, N]/N)

https://docs.mql4.com/indicators/iStdDev

Sample:

double val=iStdDev(NULL,0,10,0,MODE_EMA,PRICE_CLOSE,0);

https://docs.mql4.com/indicators/iBands

Sample:
(iBands(NULL,0,20,2,0,PRICE_CLOSE,MODE_UPPER,0)-(iBands(NULL,0,20,2,0,PRICE_CLOSE,MODE_LOWER,0)