這篇文章主要介紹了關於php實作PageRank的實例,有著一定的參考價值,現在分享給大家,有需要的朋友可以參考一下
php簡單實作PageRank演算法
<?php header("Content-type:text/html; charset=utf-8"); class PageRank{ public $map = []; public $rank = []; public $inputList = []; // example web 'a' (has input link): web 'b' public $size; public $keyValue = 0.85; public function __construct(array $map) { $this->map = $map; $this->size = count($this->map); } //init rank score and transform 'map' format to 'inputList' format public function init() { $size = $this->size; foreach ($this->map as $key => $value) { $this->inputList[$key] = []; } foreach ($this->map as $key => $value) { $this->rank[$key] = 1/$size; foreach ($value as $v) { if (empty($this->inputList[$v])) { $this->inputList[$v][] = $key; } else { array_push($this->inputList[$v], $key); } } } } public function caculate() { $tmp = $this->rank; $keyValue = $this->keyValue; $size = $this->size; foreach ($this->inputList as $key => $value) { $score = (1 - $keyValue)/$size; foreach ($value as $v) { $cc = count($this->map[$v]); if ($cc) { $score += ($keyValue*(1/$cc * $this->rank[$v])); } } $tmp[$key] = $score; } $this->rank = $tmp; } }$map = [ 'a' => ['b', 'c', 'd'],// web 'a' (has out link): web 'b', web 'c', web 'd' 'b' => ['a', 'd'], 'c' => ['b'], 'd' => ['b', 'c'], ];$example = new PageRank($map); $example->init(); echo '<pre class="brush:php;toolbar:false">';for ($i = 0; $i < 10; $i++) { $example->caculate(); var_dump($example->rank); }
以上就是本文的全部內容,希望對大家的學習有所幫助,更多相關內容請關注PHP中文網!
相關推薦:
php 透過html-table形式完成excel下載的功能實作
以上是php實作PageRank的實例的詳細內容。更多資訊請關注PHP中文網其他相關文章!