<?php

 /*

 *Naive Bayes朴素贝叶斯算法（分类算法的实现）

 */

 /*

 *把.txt中的内容读到数组中保存

 *$filename:文件名称

 */

 //--------------------------------------------------------------------

 function  getFileContent($filename)

 {

     $array = array(null);

     $content = file_get_contents($filename);

     $result = explode("\r\n",$content);

     //print_r(count($result));

     for($j=0;$j<count($result);$j++)

     {

         //print_r($result[$j]."<br>");

         $con = explode(" ",$result[$j]);

         array_push($array,$con);

     }

     array_splice($array,0,1);

     return $array;

 }

 //--------------------------------------------------------------------

 /*

 *NaiveBayes朴素贝叶斯算法

 *$test:测试文本；$train：训练文本；$flagsyes：yes；$flagsno：no

 */

 //--------------------------------------------------------------------

 function  NaiveBayes($test,$train,$flagsyes,$flagsno)

 {

     $count_yes = 0;

     $num = count($train[0]);

     for($i=1;$i<count($train);$i++)

     {

         if($train[$i][$num-1]==$flagsyes)$count_yes++;

     }

     $p_yes = $count_yes / (count($train)-1);

     $p_no = 1- $p_yes;

     $count_no = count($train)-1 - $count_yes;

     for($i=1;$i<count($test)-1;$i++)

     {

         $testnumyes = 0;

         $testnumno = 0;

         for($j=1;$j<count($train);$j++)

         {

             if(($train[$j][$i]==$test[$i])&&($train[$j][count($test)-1]==$flagsyes))$testnumyes++;

             else if(($train[$j][$i]==$test[$i])&&($train[$j][count($test)-1]==$flagsno))$testnumno++;

         }

         $array_yes[$i] = $testnumyes / $count_yes ;

         $array_no[$i] = $testnumno / $count_no ;

 /*

         print_r($testnumyes."<br>");

         print_r($testnumno."<br>");

         print_r($count_yes."<br>");

         print_r($count_no."<br>");

         print_r($array_no[$i]."<br>");

 */

     }

     $py=1;

     $pn=1;

     for($i=1;$i<count($test)-1;$i++){

         $py *= $array_yes[$i];

         $pn *= $array_no[$i];

     }

     $py *= $p_yes;

     $pn *= $p_no;

     if($py>$pn)return $flagsyes;

     else return $flagsno;

 /*    print_r($py."<br>");

         print_r($pn."<br>");

 */    

 }

 //--------------------------------------------------------------------

 $train = getFileContent("train.txt");

 $test = getFileContent("test.txt");

 for($i=1;$i<count($test);$i++)

 {

     $test[$i][count($test[0])-1] = NaiveBayes($test[$i],$train,Y,N);

 }

 /*

 *将数组中的内容读到.txt中

 */

 //--------------------------------------------------------------------

 $fp= fopen('result.txt','wb');

 for($i=0;$i<count($test);$i++)

 {

     $temp = NULL;

     for($j=0;$j<count($test[$i]);$j++)

     {

         $temp =  $test[$i][$j]."\t";

         fwrite($fp,$temp);

     }

     fwrite($fp,"\r\n");

 }

 fclose($fp);

 //--------------------------------------------------------------------

 /*

 *打印输出

 */

 //--------------------------------------------------------------------

 echo "<pre>";

 print_r($test);

 echo "</pre>";

 //--------------------------------------------------------------------

 ?>