trader_ema in wrong calculate value 
this return just simple moving avrage 
for get ema correct use this code
$number is data array and $n is number of period
example:
$number[0]    => last value
$number[n]    =>first value

function exponentialMovingAverage(array $numbers, int $n): array
{
    $numbers=array_reverse($numbers);
    $m   = count($numbers);
    $α   = 2 / ($n + 1);
    $EMA = [];

    // Start off by seeding with the first data point
    $EMA[] = $numbers[0];

    // Each day after: EMAtoday = α⋅xtoday + (1-α)EMAyesterday
    for ($i = 1; $i < $m; $i++) {
        $EMA[] = ($α * $numbers[$i]) + ((1 - $α) * $EMA[$i - 1]);
    }
    $EMA=array_reverse($EMA);
    return $EMA;
}