php-ml/tests/Math/Statistic/StandardDeviationTest.php

66 lines
2.2 KiB
PHP

<?php
declare(strict_types=1);
namespace Phpml\Tests\Math\Statistic;
use Phpml\Exception\InvalidArgumentException;
use Phpml\Math\Statistic\StandardDeviation;
use PHPUnit\Framework\TestCase;
class StandardDeviationTest extends TestCase
{
public function testStandardDeviationOfPopulationSample(): void
{
//https://pl.wikipedia.org/wiki/Odchylenie_standardowe
$delta = 0.001;
$population = [5, 6, 8, 9];
self::assertEqualsWithDelta(1.825, StandardDeviation::population($population), $delta);
//http://www.stat.wmich.edu/s216/book/node126.html
$delta = 0.5;
$population = [7100, 15500, 4400, 4400, 5900, 4600, 8800, 2000, 2750, 2550, 960, 1025];
self::assertEqualsWithDelta(4079, StandardDeviation::population($population), $delta);
$population = [9300, 10565, 15000, 15000, 17764, 57000, 65940, 73676, 77006, 93739, 146088, 153260];
self::assertEqualsWithDelta(50989, StandardDeviation::population($population), $delta);
}
public function testThrowExceptionOnEmptyArrayIfNotSample(): void
{
$this->expectException(InvalidArgumentException::class);
StandardDeviation::population([], false);
}
public function testThrowExceptionOnTooSmallArray(): void
{
$this->expectException(InvalidArgumentException::class);
StandardDeviation::population([1]);
}
/**
* @dataProvider dataProviderForSumOfSquaresDeviations
*/
public function testSumOfSquares(array $numbers, float $sum): void
{
self::assertEqualsWithDelta($sum, StandardDeviation::sumOfSquares($numbers), 0.0001);
}
public function dataProviderForSumOfSquaresDeviations(): array
{
return [
[[3, 6, 7, 11, 12, 13, 17], 136.8571],
[[6, 11, 12, 14, 15, 20, 21], 162.8571],
[[1, 2, 3, 6, 7, 11, 12], 112],
[[1, 2, 3, 4, 5, 6, 7, 8, 9, 0], 82.5],
[[34, 253, 754, 2342, 75, 23, 876, 4, 1, -34, -345, 754, -377, 3, 0], 6453975.7333],
];
}
public function testThrowExceptionOnEmptyArraySumOfSquares(): void
{
$this->expectException(InvalidArgumentException::class);
StandardDeviation::sumOfSquares([]);
}
}