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Dokumen ini menggunakan Manual laman web PHP Cina Lepaskan
(PECL trader >= 0.2.0)
trader_ema — Exponential Moving Average
$real
[, integer $timePeriod
] )
real
浮点数数组。
timePeriod
Number of period. Valid range from 2 to 100000.
Returns an array with calculated data or false on failure.
[#1] abovesense at hotmail dot com [2015-06-21 20:37:23]
Hello there,
Is someone have tried the function and can tell what is the return size digits after the decimal point, meaning what is the precision of the returned answer ?
Best,
laye
[#2] manoj dot monu23 at gmail dot com [2014-02-03 12:07:51]
the trader_ema() function does'nt work correctly , it calculate just average of last period entries. Follow the following code for trader_ema:
function EMACalculator($limit,$array)
{
$EMA_previous_day = $array[0];
//print_r($array);
$multiplier1 = (2/$limit+1);
$EMA[]=array();
$EMA = $array[0];
$Close= $array[1];
while($limit)
{
//echo"EMA is $EMA\n";
$EMA = ($Close - $EMA_previous_day) * $multiplier1 + $EMA_previous_day;
$EMA_previous_day= $EMA;
$limit--;
}
return $EMA;
}
where $limit accept the period of ema and $array : accept array of data for ema calculation.