From da070f5da606c0b07d681dbb3123233346f55515 Mon Sep 17 00:00:00 2001
From: Kurniandha Sukma Yunastrian <13516106@std.stei.itb.ac.id>
Date: Tue, 28 Apr 2020 23:50:16 +0700
Subject: [PATCH] edit string similarity algorithm
---
app/Http/Controllers/AutograderController.php | 51 ++++++++++++++++---
1 file changed, 44 insertions(+), 7 deletions(-)
diff --git a/app/Http/Controllers/AutograderController.php b/app/Http/Controllers/AutograderController.php
index 0a0bfaa..67993bd 100644
--- a/app/Http/Controllers/AutograderController.php
+++ b/app/Http/Controllers/AutograderController.php
@@ -147,23 +147,60 @@ class AutograderController extends Controller
}
}
- $results[] = AutograderController::jaccardIndex($key, $answer);
+ $results[] = AutograderController::cosine($key, $answer);
}
return $results;
}
/**
- * Get Jaccard Index score
+ * Get Cosine Similarity
*
* @return score
*/
- public function jaccardIndex($key, $answer) {
- $arr_intersection = count(array_intersect( $key, $answer ));
- $arr_union = count(array_merge( $key, $answer )) - $arr_intersection;
- $jaccard_index = $arr_intersection / $arr_union;
+ public function cosine($key, $answer) {
+ $token = [];
+ $vector1 = [];
+ $vector2 = [];
+ foreach($key as $k) {
+ if (!in_array($k, $token)) {
+ $token[] = $k;
+ $vector1[] = 0;
+ $vector2[] = 0;
+ }
+ }
+
+ foreach($answer as $k) {
+ if (!in_array($k, $token)) {
+ $token[] = $k;
+ $vector1[] = 0;
+ $vector2[] = 0;
+ }
+ }
+
+ foreach($key as $k) {
+ $vector1[array_search($k, $token)] += 1;
+ }
+ foreach($answer as $k) {
+ $vector2[array_search($k, $token)] += 1;
+ }
+
+ $dot_product = 0;
+ for($i=0; $i<count($token); $i++) {
+ $dot_product += ($vector1[$i])*($vector2[$i]);
+ }
+
+ $length1 = 0;
+ $length2 = 0;
- return $jaccard_index;
+ for($i=0; $i<count($token); $i++) {
+ $length1 += pow($vector1[$i], 2);
+ $length2 += pow($vector2[$i], 2);
+ }
+
+ $similarity = $dot_product/sqrt($length1*$length2);
+
+ return $similarity;
}
/**
--
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