1 $data=array('a'=>array('a'=> 2.5, 'b'=> 3.5, 'c'=> 3.0,'d'=> 3.5, 'e'=> 2.5, 'f'=> 3.0),
2 'b'=>array('a'=> 3.0, 'b'=> 3.5, 'c'=> 1.5, 'd'=> 5.0, 'f'=> 3.0, 'e'=> 3.5),
3 'c'=>array('a'=> 2.5, 'b'=> 3.0, 'd'=> 3.5,'f'=> 4.0),
4 'd'=>array('b'=> 3.5, 'c'=> 3.0, 'f'=> 4.5,'d'=> 4.0, 'e'=> 2.5),
5 'e'=>array('a'=> 3.0, 'b'=> 4.0, 'c'=> 2.0,'d'=> 3.0, 'f'=> 3.0, 'e'=> 2.0),
6 'f'=>array('a'=> 3.0, 'b'=> 4.0, 'f'=> 3.0,'d'=> 5.0, 'e'=> 3.5),
7 'g'=>array('b'=> 4.5,'e'=> 1.0,'d'=> 4.0),
8 'h'=>array('aa'=> 5.0 ));
9
10 function test($arr,$person,$anotherPerson){
11 if(!array_key_exists($person, $arr) || !array_key_exists($anotherPerson, $arr)){
12 return 0;
13 }
14 $mark = 0;
15 $result = 0;
16 foreach($arr[$person] as $key=>$value){
17 if(array_key_exists($key,$arr[$anotherPerson])){
18 $mark++;
19 $result += pow($value-$arr[$anotherPerson][$key],2);
20 }
21 }
22 if($mark == 0){
23 return 0;
24 }
25 return 1/(1+sqrt($result));
26 }
27
28 $result = test($data,'a','b');
29 echo 'similarity is:'.$result;
