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Editing: LeavePOut.php
<?php namespace Rubix\ML\CrossValidation; use Rubix\ML\Learner; use Rubix\ML\Parallel; use Rubix\ML\Estimator; use Rubix\ML\Helpers\Stats; use Rubix\ML\Backends\Serial; use Rubix\ML\Datasets\Labeled; use Rubix\ML\Datasets\Dataset; use Rubix\ML\Traits\Multiprocessing; use Rubix\ML\CrossValidation\Metrics\Metric; use Rubix\ML\Backends\Tasks\TrainAndValidate; use Rubix\ML\Specifications\EstimatorIsCompatibleWithMetric; use Rubix\ML\Exceptions\InvalidArgumentException; /** * Leave P Out * * Leave P Out tests a learner with a unique holdout set of size p for each iteration until * all samples have been tested. Although Leave P Out can take long with large datasets and * small values of p, it is especially suited for small datasets. * * @category Machine Learning * @package Rubix/ML * @author Andrew DalPino */ class LeavePOut implements Validator, Parallel { use Multiprocessing; /** * The number of samples to leave out each round for testing. * * @var int */ protected int $p; /** * @param int $p * @throws InvalidArgumentException */ public function __construct(int $p = 10) { if ($p < 1) { throw new InvalidArgumentException('P must be greater' . " than 0, $p given."); } $this->p = $p; $this->backend = new Serial(); } /** * Test the estimator with the supplied dataset and return a validation score. * * @param Learner $estimator * @param Labeled $dataset * @param Metric $metric * @throws InvalidArgumentException * @return float */ public function test(Learner $estimator, Labeled $dataset, Metric $metric) : float { EstimatorIsCompatibleWithMetric::with($estimator, $metric)->check(); $n = (int) round($dataset->numSamples() / $this->p); $this->backend->flush(); for ($i = 0; $i < $n; ++$i) { $training = clone $dataset; $testing = $training->splice($i * $this->p, $this->p); $this->backend->enqueue( new TrainAndValidate($estimator, $training, $testing, $metric) ); } $scores = $this->backend->process(); return Stats::mean($scores); } /** * Return the string representation of the object. * * @internal * * @return string */ public function __toString() : string { return "Leave P Out (p: {$this->p})"; } }
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