public static function isNumber($input, array $options = array())
    {
        if (!self::_getUniCodeSupport()) {
            trigger_error("Sorry, your PCRE extension does not support UTF8 which is needed for the I18N core", E_USER_NOTICE);
        }

        $options = self::_checkOptions($options) + self::$_options;

        // Get correct signs for this locale
        $symbols = Zend_Locale_Data::getList($options['locale'],'symbols');

        $regexs = Zend_Locale_Format::_getRegexForType('decimalnumber', $options);
        $regexs = array_merge($regexs, Zend_Locale_Format::_getRegexForType('scientificnumber', $options));
        if (!empty($input) && ($input[0] == $symbols['decimal'])) {
            $input = 0 . $input;
        }
        foreach ($regexs as $regex) {
            preg_match($regex, $input, $found);
            if (isset($found[0])) {
                return true;
            }
        }

        return false;
    }