A simple Bag of Words example in PHP

Below is a minimal Bag of Words implementation in pure PHP. We take three short documents, tokenize them, build a shared vocabulary, and convert each document into a word-frequency vector.

Example of use


                
<?php

$documents = [
    'Cat eats fish',
    'Cat likes fish',
    'Dog eats meat',
];

include 'code.php';

echo 'Vocabulary: ' . implode(', ', $vocab) . PHP_EOL . PHP_EOL;

foreach ($bowVectors as $i => $vector) {
    echo 'Document ' . ($i + 1) . ':' . PHP_EOL;

    foreach ($vector as $word => $count) {
        echo "  $word => $count" . PHP_EOL;
    }

    if ($i < 2) {
        echo PHP_EOL;
    }
}

Documents:


            Cat eats fish
Cat likes fish
Dog eats meat

Result: Memory: 0.006 Mb Time running: < 0.001 sec.


                Vocabulary: Cat, eats, fish, likes, Dog, meat

Document 1:
  Cat => 1
  eats => 1
  fish => 1
  likes => 0
  Dog => 0
  meat => 0

Document 2:
  Cat => 1
  eats => 0
  fish => 1
  likes => 1
  Dog => 0
  meat => 0

Document 3:
  Cat => 0
  eats => 1
  fish => 0
  likes => 0
  Dog => 1
  meat => 1