PhpScience\PageRank\Service\PageRankAlgorithm\Normalizer

Complexity

Total Complexity

6

Size/Duplication

Total Lines	50
Duplicated Lines	0 %

Test Coverage

Coverage

100%

Importance

Changes

0

4 Methods

Rating	Name	Duplication	Size	Complexity
A	normalize()	0	14	2
A	getScaledRank()	0	9	1
A	__construct()	0	6	1
A	getDivider()	0	9	2

<?php


declare(strict_types=1);


namespace PhpScience\PageRank\Service\PageRankAlgorithm;


use PhpScience\PageRank\Data\NodeCollectionInterface;


class Normalizer implements NormalizerInterface

{

    private float $scaleBottom;

    private float $scaleTop;


    public function __construct(

        float $scaleBottom = 1,

        float $scaleTop = 10

    ) {

        $this->scaleBottom = $scaleBottom;

        $this->scaleTop = $scaleTop;

    }


    public function normalize(

        NodeCollectionInterface $nodeCollection,

        float $lowestRank,

        float $highestRank

    ): void {

        $divider = $this->getDivider($lowestRank, $highestRank);


        foreach ($nodeCollection->getNodes() as $node) {

            $rank = $this->getScaledRank(

                $node->getRank(),

                $lowestRank,

                $divider

            );

            $node->setRank($rank);

        }

    }


    private function getDivider(float $lowestRank, float $highestRank): float

    {

        $divider = $highestRank - $lowestRank;


        if (.0 === $divider) {

The condition 0.0 === $divider is always false.

            $divider = 1;

        }


        return $divider;

    }


    private function getScaledRank(

        float $value,

        float $lowestRank,

        float $divider

    ): float {

        $normalized = ($value - $lowestRank) / $divider;

        $multiplier = $this->scaleTop - $this->scaleBottom;


        return ($normalized * $multiplier) + $this->scaleBottom;

    }

}