Weighted Ratings

A lightweight PHP library for calculating the Wilson Lower Bound Score and Bayesian Approximation weights for sorting algorithms based on user feedback.

Installation

Weighted Ratings Library is available via Composer. Just add this line to your composer.json file:

"ilicmiljan/weighted-ratings": "^1.0"

or you can run:

composer require ilicmiljan/weighted-ratings

Note that the vendor folder and the vendor/autoload.php script are generated by Composer and they are not part of Weighted Ratings Library.

Configuration

Available Formulas

RatingWeightCalculator::FORMULA_WILSON_LOWER_BOUND
RatingWeightCalculator::FORMULA_BAYESIAN_APPROXIMATION

Optional Configuration Parameters

• ausmeNegativeRatingisLessThan - Number of stars in the rating that are assumed as negative (Default: 3)
• confidence - Statistical Confidence used in Formulas (Default: 0.95)

Without RatingWeightConfig

You can use default optional config parameters to calculate weights without instantiating RateLimiterConfig. This can be achieved by setting the formula in the instance of RatingWeightCalculator.

Using RatingWeightConfig

You can create a new instance of RatingWeightConfig with all the parameters and pass it to the RatingWeightCalculator.

Changing Formula

The formula for one instance of RatingWeightCalculator can be set only once. Changing formula in the runtime will throw an exception.

Usage

With Default Config Parameters

$weightCalculator = new RatingWeightCalculator();

$ratingWeight = $weightCalculator->formula(RatingWeightCalculator::FORMULA_WILSON_LOWER_BOUND)
    ->calculateWeight([2,4,6,12,24]);

With Custom Parameters

$weightCalculator = new RatingWeightCalculator(
    new RatingWeightConfig(RatingWeightCalculator::FORMULA_WILSON_LOWER_BOUND, 5, 0.9)
);

$ratingWeight = $weightCalculator->calculateWeight([2,4,6,12,24,48,92,184,]);

Testing

To run Unit Tests inside this library you can use this command:

./vendor/bin/phpunit

Infection PHP Metrics:

• Mutation Score Indicator (MSI): 98%
• Mutation Code Coverage: 100%
• Covered Code MSI: 98%