40 lines
1.2 KiB
PHP
40 lines
1.2 KiB
PHP
<?php
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declare(strict_types=1);
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namespace Phpml\Tests\FeatureSelection;
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use Phpml\Exception\InvalidArgumentException;
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use Phpml\FeatureSelection\VarianceThreshold;
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use PHPUnit\Framework\TestCase;
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final class VarianceThresholdTest extends TestCase
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{
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public function testVarianceThreshold(): void
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{
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$samples = [[0, 0, 1], [0, 1, 0], [1, 0, 0], [0, 1, 1], [0, 1, 0], [0, 1, 1]];
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$transformer = new VarianceThreshold(0.8 * (1 - 0.8)); // 80% of samples - boolean features are Bernoulli random variables
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$transformer->fit($samples);
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$transformer->transform($samples);
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// expecting to remove first column
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self::assertEquals([[0, 1], [1, 0], [0, 0], [1, 1], [1, 0], [1, 1]], $samples);
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}
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public function testVarianceThresholdWithZeroThreshold(): void
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{
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$samples = [[0, 2, 0, 3], [0, 1, 4, 3], [0, 1, 1, 3]];
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$transformer = new VarianceThreshold();
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$transformer->fit($samples);
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$transformer->transform($samples);
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self::assertEquals([[2, 0], [1, 4], [1, 1]], $samples);
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}
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public function testThrowExceptionWhenThresholdBelowZero(): void
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{
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$this->expectException(InvalidArgumentException::class);
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new VarianceThreshold(-0.1);
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}
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}
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