(PECL trader >= 0.2.0)
trader_mfi — Money Flow Index
$high
, array $low
, array $close
, array $volume
[, int $timePeriod
] )
high高价，浮点数数组。
low低价，浮点数数组。
close收盘价，浮点数数组。
volume成交量，浮点数数组。
timePeriodNumber of period. Valid range from 2 to 100000.
Returns an array with calculated data or false on failure.