(PECL trader >= 0.2.0)
trader_bbands — Bollinger Bands
$real
   [, integer $timePeriod
   [, float $nbDevUp
   [, float $nbDevDn
   [, integer $mAType
  ]]]] )
realArray of real values.
timePeriodNumber of period. Valid range from 2 to 100000.
nbDevUpDeviation multiplier for upper band. Valid range from TRADER_REAL_MIN to TRADER_REAL_MAX.
nbDevDnDeviation multiplier for lower band. Valid range from TRADER_REAL_MIN to TRADER_REAL_MAX.
mATypeType of Moving Average. TRADER_MA_TYPE_* series of constants should be used.
Returns an array with calculated data or false on failure.