I would like to compare to set of text and get how similar/relevant they are to each other, I use similar_text(), but i found out its not as accurate

Question

I would like to compare to set of text and get how similar/relevant they are to each other, I use similar_text(), but i found out its not as accurate. Thank you.

For example the following text gives me 66%

Text1: Innovation game, eat, sleep, breathe innovation. It love creativity & passion power Internet drives . We understand time greatest asset, challege meet deadline.

Text2: Soviet union communist policy; Germany league organization disguise enermies beaten wanted.

My code is as below:

echo $student_answer = removeCommonWords($answer)."<br><br>";

$student_answer = strip_tags($student_answer);

echo $memo = removeCommonWords2($memo)."<br><br>";

echo similar_text($memo, $student_answer);

Answer 1

You can use the JS version:

http://phpjs.org/functions/similar_text/

The JS code shows you the precent code (you can modify the code):

return (sum * 200) / (firstLength + secondLength);

I hope this will help you!

EDIT:

How to use similar_text in JS?

1. Create a file named similar_text.js and copy&paste this code in it:

    function similar_text (first, second, percent) {
    // http://kevin.vanzonneveld.net
    // +   original by: Rafał Kukawski (http://blog.kukawski.pl)
    // +   bugfixed by: Chris McMacken
    // +   added percent parameter by: Markus Padourek (taken from http://www.kevinhq.com/2012/06/php-similartext-function-in-javascript_16.html)
    // *     example 1: similar_text('Hello World!', 'Hello phpjs!');
    // *     returns 1: 7
    // *     example 2: similar_text('Hello World!', null);
    // *     returns 2: 0
    // *     example 3: similar_text('Hello World!', null, 1);
    // *     returns 3: 58.33
    if (first === null || second === null || typeof first === 'undefined' || typeof second === 'undefined') {
      return 0;
    }
   
    first += '';
    second += '';
   
    var pos1 = 0,
      pos2 = 0,
      max = 0,
      firstLength = first.length,
      secondLength = second.length,
      p, q, l, sum;
   
    max = 0;
   
    for (p = 0; p < firstLength; p++) {
      for (q = 0; q < secondLength; q++) {
        for (l = 0;
        (p + l < firstLength) && (q + l < secondLength) && (first.charAt(p + l) === second.charAt(q + l)); l++);
        if (l > max) {
          max = l;
          pos1 = p;
          pos2 = q;
        }
      }
    }
   
    sum = max;
   
    if (sum) {
      if (pos1 && pos2) {
        sum += this.similar_text(first.substr(0, pos2), second.substr(0, pos2));
      }
   
      if ((pos1 + max < firstLength) && (pos2 + max < secondLength)) {
        sum += this.similar_text(first.substr(pos1 + max, firstLength - pos1 - max), second.substr(pos2 + max, secondLength - pos2 - max));
      }
    }
   
    if (!percent) {
      return sum;
    } else {
      return (sum * 200) / (firstLength + secondLength);
    }
   }
   

2. In your put the following line:

     <script type="text/JavaScript" src="YOUR_PATH/similar_text.js"></script>
   

3. Now you can use it in your body:

     <script>
      similar_text('Hello World!', 'Hello phpjs!');
     </script>
   

It will output 7.

Hope this wil help you!