87 lines
2.4 KiB
PHP
87 lines
2.4 KiB
PHP
<?php
|
|
|
|
declare(strict_types=1);
|
|
|
|
namespace Phpml\Metric;
|
|
|
|
use Phpml\Exception\InvalidArgumentException;
|
|
use Phpml\Math\Statistic\Correlation;
|
|
use Phpml\Math\Statistic\Mean;
|
|
|
|
final class Regression
|
|
{
|
|
public static function meanSquaredError(array $targets, array $predictions): float
|
|
{
|
|
self::assertCountEquals($targets, $predictions);
|
|
|
|
$errors = [];
|
|
foreach ($targets as $index => $target) {
|
|
$errors[] = (($target - $predictions[$index]) ** 2);
|
|
}
|
|
|
|
return Mean::arithmetic($errors);
|
|
}
|
|
|
|
public static function meanSquaredLogarithmicError(array $targets, array $predictions): float
|
|
{
|
|
self::assertCountEquals($targets, $predictions);
|
|
|
|
$errors = [];
|
|
foreach ($targets as $index => $target) {
|
|
$errors[] = log((1 + $target) / (1 + $predictions[$index])) ** 2;
|
|
}
|
|
|
|
return Mean::arithmetic($errors);
|
|
}
|
|
|
|
public static function meanAbsoluteError(array $targets, array $predictions): float
|
|
{
|
|
self::assertCountEquals($targets, $predictions);
|
|
|
|
$errors = [];
|
|
foreach ($targets as $index => $target) {
|
|
$errors[] = abs($target - $predictions[$index]);
|
|
}
|
|
|
|
return Mean::arithmetic($errors);
|
|
}
|
|
|
|
public static function medianAbsoluteError(array $targets, array $predictions): float
|
|
{
|
|
self::assertCountEquals($targets, $predictions);
|
|
|
|
$errors = [];
|
|
foreach ($targets as $index => $target) {
|
|
$errors[] = abs($target - $predictions[$index]);
|
|
}
|
|
|
|
return (float) Mean::median($errors);
|
|
}
|
|
|
|
public static function r2Score(array $targets, array $predictions): float
|
|
{
|
|
self::assertCountEquals($targets, $predictions);
|
|
|
|
return Correlation::pearson($targets, $predictions) ** 2;
|
|
}
|
|
|
|
public static function maxError(array $targets, array $predictions): float
|
|
{
|
|
self::assertCountEquals($targets, $predictions);
|
|
|
|
$errors = [];
|
|
foreach ($targets as $index => $target) {
|
|
$errors[] = abs($target - $predictions[$index]);
|
|
}
|
|
|
|
return (float) max($errors);
|
|
}
|
|
|
|
private static function assertCountEquals(array &$targets, array &$predictions): void
|
|
{
|
|
if (count($targets) !== count($predictions)) {
|
|
throw new InvalidArgumentException('Targets count must be equal with predictions count');
|
|
}
|
|
}
|
|
}
|