$re = '/\b\d+\.\d\d\K\d+,/m';
$str = '57.0977452, 56.11753043, 55.16086013, 54.22551611, 53.3095779,
';
$subst = "";
$result = preg_replace($re, $subst, $str);
echo "The result of the substitution is ".$result;
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php