# trader_bbands

(PECL trader >= 0.2.0)

trader_bbands — Bollinger Bands

### 说明

trader_bbands ( array `$real` [, int `$timePeriod` [, float `$nbDevUp` [, float `$nbDevDn` [, int `$mAType` ]]]] ) : array

### 参数

`real`

  浮点数数组。

`timePeriod`

  Number of period. Valid range from 2 to 100000.

`nbDevUp`

  Deviation multiplier for upper band. Valid range from TRADER_REAL_MIN to TRADER_REAL_MAX.

`nbDevDn`

  Deviation multiplier for lower band. Valid range from TRADER_REAL_MIN to TRADER_REAL_MAX.

`mAType`

  Type of Moving Average. TRADER_MA_TYPE_* series of constants should be used.

### 返回值

Returns an array with calculated data or false on failure.