<?php
$summary = <<< summary
this is a test. this is a test. this is a test. this is a test. this is a test. this is a test.
this is a test. this is a test. this is a test. this is a test. this is a test. this is a test.
this is a test. this is a test. this is a test. this is a test. this is a test. this is a test.
summary;
$words = str_word_count($summary,2);
$frequency = array_count_values($words);
print_r($frequency);
?>