Cosine::run() - Code Metrics - stojg/recommend - Measure and Improve Code Quality continuously with Scrutinizer

Cosine::run() B
last analyzed 2015-12-03 06:43 UTC

↳ Parent: Cosine

Complexity

Conditions	5
Paths	9

Size

Total Lines	24
Code Lines	16

Duplication

Lines	0
Ratio	0 %

Importance

Changes	4
Bugs	1	Features	0

Metric	Value
c	4
b	1
f	0
dl	0
loc	24
rs	8.5126
cc	5
eloc	16
nc	9
nop	2

<?php

namespace stojg\recommend\strategy;

/**
 * Cosine similarity is a measure of similarity between two vectors of an inner product space that measures the 
 * cosine of the angle between them. The cosine of 0° is 1, and it is less than 1 for any other angle. It is thus a 
 * judgement of orientation and not magnitude: two vectors with the same orientation have a Cosine similarity of 1, 
 * two vectors at 90° have a  similarity of 0, and two vectors diametrically opposed have a similarity of -1, 
 * independent of their magnitude.
 */
class Cosine
{
    /**
     * Use if the data is sparse.
     */
    public function run($rating1, $rating2)
    {
        $dotProduct = 0;
        $sqrLenght1 = 0;
        foreach ($rating1 as $item => $rating) {
            if (!isset($rating2[$item])) {
                continue;
            }
            $sqrLenght1 += pow($rating, 2);
            $dotProduct += $rating * $rating2[$item];
        }
        if (!$sqrLenght1) {
            return false;
        }
        $length1 = sqrt($sqrLenght1);

        $sqrLength2 = 0;
        foreach ($rating2 as $item => $rating) {
            $sqrLength2 += pow($rating, 2);
        }
        $length2 = sqrt($sqrLength2);

        return 1 - abs($dotProduct / ($length1 * $length2));
    }
}


1			<?php
2
3			namespace stojg\recommend\strategy;
4
5			/**
6			* Cosine similarity is a measure of similarity between two vectors of an inner product space that measures the
7			* cosine of the angle between them. The cosine of 0° is 1, and it is less than 1 for any other angle. It is thus a
8			* judgement of orientation and not magnitude: two vectors with the same orientation have a Cosine similarity of 1,
9			* two vectors at 90° have a similarity of 0, and two vectors diametrically opposed have a similarity of -1,
10			* independent of their magnitude.
11			*/
12			class Cosine
13			{
14			/**
15			* Use if the data is sparse.
16			*/
17			public function run($rating1, $rating2)
18			{
19			$dotProduct = 0;
20			$sqrLenght1 = 0;
21			foreach ($rating1 as $item => $rating) {
22			if (!isset($rating2[$item])) {
23			continue;
24			}
25			$sqrLenght1 += pow($rating, 2);
26			$dotProduct += $rating * $rating2[$item];
27			}
28			if (!$sqrLenght1) {
29			return false;
30			}
31			$length1 = sqrt($sqrLenght1);
32
33			$sqrLength2 = 0;
34			foreach ($rating2 as $item => $rating) {
35			$sqrLength2 += pow($rating, 2);
36			}
37			$length2 = sqrt($sqrLength2);
38
39			return 1 - abs($dotProduct / ($length1 * $length2));
40			}
41			}
42

stojg / recommend

Cosine::run() B last analyzed 2015-12-03 06:43 UTC

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Cosine::run() B
last analyzed 2015-12-03 06:43 UTC