How to extract keywords from bengali text using PHP - php

Question

I want to extract keywords automatically from Bengali text files using php.I have this code for reading a Bengali text file.
<?php
$target_path = $_FILES['uploadedfile']['name'];
header('Content-Type: text/plain;charset=utf-8');
$fp = fopen($target_path, 'r') or die("Can't open CEDICT.");
$i = 0;
while ($line = fgets($fp, 1024))
{
print $line;
$i++;
}
fclose($fp) or die("Can't close file.");
And I found following codes to extract most common 10 keywords but it's not working for Bengali texts. What changes should I make?
function extractCommonWords($string){
$stopWords = array('i','a','about','an','and','are','as','at','be','by','com','de','en','for','from','how','in','is','it','la','of','on','or','that','the','this','to','was','what','when','where','who','will','with','und','the','www');
$string = preg_replace('/\s\s+/i', '', $string); // replace whitespace
$string = trim($string); // trim the string
$string = preg_replace('/[^a-zA-Z0-9 -]/', '', $string); // only take alphanumerical characters, but keep the spaces and dashes too…
$string = strtolower($string); // make it lowercase
preg_match_all('/\b.*?\b/i', $string, $matchWords);
$matchWords = $matchWords[0];
foreach ( $matchWords as $key=>$item ) {
if ( $item == '' || in_array(strtolower($item), $stopWords) || strlen($item) <= 3 ) {
unset($matchWords[$key]);
}
}
$wordCountArr = array();
if ( is_array($matchWords) ) {
foreach ( $matchWords as $key => $val ) {
$val = strtolower($val);
if ( isset($wordCountArr[$val]) ) {
$wordCountArr[$val]++;
} else {
$wordCountArr[$val] = 1;
}
}
}
arsort($wordCountArr);
$wordCountArr = array_slice($wordCountArr, 0, 10);
return $wordCountArr;
}
Please help :(

Answer 1

You should make simple changes:
replace stopwords in $stopWords array with proper Bengali stopwords
remove this string $string = preg_replace('/[^a-zA-Z0-9 -]/', '', $string); because Bengali sybmols doesn't match this pattern
Full code looks like:
<?php
function extractCommonWords($string){
// replace array below with proper Bengali stopwords
$stopWords = array('i','a','about','an','and','are','as','at','be','by','com','de','en','for','from','how','in','is','it','la','of','on','or','that','the','this','to','was','what','when','where','who','will','with','und','the','www');
$string = preg_replace('/\s\s+/i', '', $string); // replace whitespace
$string = trim($string); // trim the string
// remove this preg_replace because Bengali sybmols doesn't match this pattern
// $string = preg_replace('/[^a-zA-Z0-9 -]/', '', $string); // only take alphanumerical characters, but keep the spaces and dashes too…
$string = strtolower($string); // make it lowercase
preg_match_all('/\s.*?\s/i', $string, $matchWords);
$matchWords = $matchWords[0];
foreach ( $matchWords as $key=>$item ) {
if ( $item == '' || in_array(strtolower(trim($item)), $stopWords) || strlen($item) <= 3 ) {
unset($matchWords[$key]);
}
}
$wordCountArr = array();
if ( is_array($matchWords) ) {
foreach ( $matchWords as $key => $val ) {
$val = trim(strtolower($val));
if ( isset($wordCountArr[$val]) ) {
$wordCountArr[$val]++;
} else {
$wordCountArr[$val] = 1;
}
}
}
arsort($wordCountArr);
$wordCountArr = array_slice($wordCountArr, 0, 10);
return $wordCountArr;
}
$string = <<<EOF
টিপ বোঝে না, টোপ বোঝে না টিপ বোঝে না, কেমন বাপু লোক
EOF;
var_dump(extractCommonWords($string), $string);
Output will be:
array(4) {
["বোঝে"]=>
int(2)
["টোপ"]=>
int(1)
["না"]=>
int(1)
["কেমন"]=>
int(1)
}
string(127) "টিপ বোঝে না, টোপ বোঝে না টিপ বোঝে না, কেমন বাপু লোক"