$re = '/^(((-?(\d{1,3})(\.\d+)?) (-?(\d{1,3})(\.\d+)?)),\s*){3,}$/';
$str = '41.278198 95.914285,
41.278198 -95.914285,
41.278198 -95.914285,';
preg_match($re, $str, $matches, PREG_OFFSET_CAPTURE, 0);
// Print the entire match result
var_dump($matches);
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