prepare($sql);
$stmt->execute();
$messages = $stmt->fetchAll(PDO::FETCH_ASSOC);
//total measurement internal array
$total_measurement = [];
foreach ($messages as $message){
//Cleanup input array
$message = json_decode($message['description'],true);
$message = $message["doubletestvalues"];
foreach ($message as $measure){
//Filter out correct measurements
if ($measure['pass'] === true){
$total_measurement[$measure['name']][] = $measure['measure'];
}
}
}
//result array
$total_results = [];
//print "";
//print_r($total_measurement);
//print "
";
foreach ($total_measurement as $key => $value){
$total_results[$key]['average'] = average($value);
$total_results[$key]['median'] = calculateMedian($value);
$total_results[$key]['stdev'] = standDeviation($value);
}
print "";
print_r($total_results);
print "
";
function standDeviation($arr)
{
$num_of_elements = count($arr);
$variance = 0.0;
// Calculate mean using array_sum() method
$average = array_sum($arr) / $num_of_elements;
foreach($arr as $i)
{
// Sum of squares of differences between all numbers and means.
$variance += pow(($i - $average), 2);
}
return (float)sqrt($variance / $num_of_elements);
}
function average($arr)
{
$num_of_elements = count($arr);
$average = array_sum($arr) / $num_of_elements;
return $average;
}
function calculateMedian($array) {
if (empty($array)) {
return null;
} else {
sort($array);
$lowMiddle = $array[floor((count($array) - 1) / 2)];
$highMiddle = $array[ceil((count($array) - 1) / 2)];
return ($lowMiddle + $highMiddle) / 2;
}
}
?>