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<?php
//
// +----------------------------------------------------------------------+
// | PHP Version 4 |
// +----------------------------------------------------------------------+
// | Copyright (c) 1997-2004 The PHP Group |
// +----------------------------------------------------------------------+
// | This source file is subject to version 2.02 of the PHP license, |
// | that is bundled with this package in the file LICENSE, and is |
// | available at through the world-wide-web at |
// | http://www.php.net/license/2_02.txt. |
// | If you did not receive a copy of the PHP license and are unable to |
// | obtain it through the world-wide-web, please send a note to |
// | license@php.net so we can mail you a copy immediately. |
// +----------------------------------------------------------------------+
// | Authors : David Costa <gurugeek@php.net> |
// | Sterling Hughes <sterling@php.net> |
// +----------------------------------------------------------------------+
// $Id: Roman.php,v 1.20 2007/06/28 10:48:41 cweiske Exp $
// {{{ Numbers_Roman
/**
* Provides utilities to convert roman numerals to arabic numbers
* and convert arabic numbers to roman numerals.
*
* @author David Costa <gurugeek@php.net>
* @author Sterling Hughes <sterling@php.net>
* @package Numbers_Roman
*/
/**
* Needed for error handling
*/
require_once 'PEAR.php';
/**
* Provides utilities to convert roman numerals to
* arabic numbers and convert arabic numbers to roman numerals.
*
* Supports lower case input and output and some further conversion
* functions.
*
* @access public
* @author David Costa <gurugeek@php.net>
* @author Sterling Hughes <sterling@php.net>
* @package Numbers_Roman
*/
class Numbers_Roman
{
// {{{ toNumber()
/**
* Converts a roman numeral to a number
*
* @param string $roman The roman numeral to convert lower cased
* numerals are converted into uppercase
* @return integer $num The number corresponding to the
* given roman numeral
* @access public
*/
function toNumber($roman)
{
/*
* insure that matching works
*/
$roman = strtoupper($roman);
/*
* remove all inapropriate characters
*/
$roman = preg_replace('/[^_MDCLXVUI]/', '', $roman);
/*
* replace u with v, in case the number being parsed
* uses a variant character set
*/
$roman = str_replace('U', 'V', $roman);
/*
* Replacing the Numerals representing an integer higher then 4000
* e.g. _X represent 10 000 _L represent 50 000 etc
* we first convert them into single characters
*/
$roman = str_replace('_V', 'S', $roman);
$roman = str_replace('_X', 'R', $roman);
$roman = str_replace('_L', 'P', $roman);
$roman = str_replace('_C', 'Q', $roman);
$roman = str_replace('_D', 'O', $roman);
$roman = str_replace('_M', 'N', $roman);
/*
* now for the conversion table.
* the characters must be precisely in the same order
* as the number array members they represent. This way,
* their position in the string precisely represents
* the array key of the corresponding number.
*/
$conv_chars = 'IVXLCDMSRPQON0';
$conv = array(
1,
5,
10,
50,
100,
500,
1000,
5000,
10000,
50000,
100000,
500000,
1000000,
0
);
/*
* initialize variables
*/
$arabic = 0;
$state = 0;
$sidx = 0;
$pos = 0;
$len = strlen($roman) - 1;
/*
* the numeral string is processed from right to left.
*/
while ($len >= 0) {
$sidx = $len;
/*
* finds the array key by checking the location
* of the character in the string $conv_chars
*/
$pos = strpos($conv_chars, $roman[$sidx]);
/*
* If a character is not found in the string,
* generate an error message using PEAR_Error
*/
if ($pos === false) {
PEAR::raiseError('Numbers_Roman::toNumber error: Invalid characters in input',0, PEAR_ERROR_TRIGGER);
} else {
/*
* if the precedingly processed numeral is higher,
* subtract the value of the current numeral.
*/
if ($state > $conv[$pos]) {
if (!$state2){
$arabic -= $conv[$pos];
$state2 = true;
} else {
PEAR::raiseError('Numbers_Roman::toNumber error: Invalid numeral order in input (multiple subtraction)',0, PEAR_ERROR_TRIGGER);
}
/*
* else, add the value of the numeral to our number
* and remember it for the if clause directly
* preceding this else
*/
} else {
$arabic += $conv[$pos];
$state = $conv[$pos];
$state2 = false;
}
}
/*
* move one place to the left
*/
$len--;
}
return $arabic;
}
// }}}
// {{{ toRoman()
/**
* A backwards compatibility alias for toNumeral()
*
* @access private
*/
function toRoman($num, $uppercase = true)
{
return Numbers_Roman::toNumeral($num, $uppercase);
}
// }}}
// {{{ toNumeral()
/**
* Converts a number to its roman numeral representation
*
* @param integer $num An integer between 0 and 3999
* inclusive that should be converted
* to a roman numeral integers higher than
* 3999 are supported from version 0.1.2
* Note:
* For an accurate result the integer shouldn't be higher
* than 5 999 999. Higher integers are still converted but
* they do not reflect an historically correct Roman Numeral.
*
* @param bool $uppercase Uppercase output: default true
*
* @param bool $html Enable html overscore required for
* integers over 3999. default true
* @return string $roman The corresponding roman numeral
*
* @access public
*/
function toNumeral($num, $uppercase = true, $html = true)
{
$conv = array(10 => array('X', 'C', 'M'),
5 => array('V', 'L', 'D'),
1 => array('I', 'X', 'C'));
$roman = '';
if ($num < 0) {
return '';
}
$num = (int) $num;
$digit = (int) ($num / 1000);
$num -= $digit * 1000;
while ($digit > 0) {
$roman .= 'M';
$digit--;
}
for ($i = 2; $i >= 0; $i--) {
$power = pow(10, $i);
$digit = (int) ($num / $power);
$num -= $digit * $power;
if (($digit == 9) || ($digit == 4)) {
$roman .= $conv[1][$i] . $conv[$digit+1][$i];
} else {
if ($digit >= 5) {
$roman .= $conv[5][$i];
$digit -= 5;
}
while ($digit > 0) {
$roman .= $conv[1][$i];
$digit--;
}
}
}
/*
* Preparing the conversion of big integers over 3999.
* One of the systems used by the Romans to represent 4000 and
* bigger numbers was to add an overscore on the numerals.
* Because of the non ansi equivalent if the html output option
* is true we will return the overline in the html code if false
* we will return a _ to represent the overscore to convert from
* numeral to arabic we will always expect the _ as a
* representation of the html overscore.
*/
if ($html == true) {
$over = '<span style="text-decoration:overline;">';
$overe = '</span>';
} elseif ($html == false) {
$over = '_';
$overe = '';
}
/*
* Replacing the previously produced multiple MM with the
* relevant numeral e.g. for 1 000 000 the roman numeral is _M
* (overscore on the M) for 900 000 is _C_M (overscore on both
* the C and the M) We initially set the replace to AFS which
* will be later replaced with the M.
*
* 500 000 is _D (overscore D) in Roman Numeral
* 400 000 is _C_D (overscore on both C and D) in Roman Numeral
* 100 000 is _C (overscore C) in Roman Numeral
* 90 000 is _X_C (overscore on both X and C) in Roman Numeral
* 50 000 is _L (overscore L) in Roman Numeral
* 40 000 is _X_L (overscore on both X and L) in Roman Numeral
* 10 000 is _X (overscore X) in Roman Numeral
* 5 000 is _V (overscore V) in Roman Numeral
* 4 000 is M _V (overscore on the V only) in Roman Numeral
*
* For an accurate result the integer shouldn't be higher then
* 5 999 999. Higher integers are still converted but they do not
* reflect an historically correct Roman Numeral.
*/
$roman = str_replace(str_repeat('M', 1000),
$over.'AFS'.$overe, $roman);
$roman = str_replace(str_repeat('M', 900),
$over.'C'.$overe.$over.'AFS'.$overe, $roman);
$roman = str_replace(str_repeat('M', 500),
$over.'D'.$overe, $roman);
$roman = str_replace(str_repeat('M', 400),
$over.'C'.$overe.$over.'D'.$overe, $roman);
$roman = str_replace(str_repeat('M', 100),
$over.'C'.$overe, $roman);
$roman = str_replace(str_repeat('M', 90),
$over.'X'.$overe.$over.'C'.$overe, $roman);
$roman = str_replace(str_repeat('M', 50),
$over.'L'.$overe, $roman);
$roman = str_replace(str_repeat('M', 40),
$over.'X'.$overe.$over.'L'.$overe, $roman);
$roman = str_replace(str_repeat('M', 10),
$over.'X'.$overe, $roman);
$roman = str_replace(str_repeat('M', 5),
$over.'V'.$overe, $roman);
$roman = str_replace(str_repeat('M', 4),
'M'.$over.'V'.$overe, $roman);
/*
* Replacing AFS with M used in both 1 000 000
* and 900 000
*/
$roman = str_replace('AFS', 'M', $roman);
/*
* Make HTML output more readable by combining span tags
* where possible.
*/
if ($html == true) {
$roman = str_replace($overe.$over, '', $roman);
}
/*
* Checking for lowercase output
*/
if ($uppercase == false) {
$roman = strtolower($roman);
}
return $roman;
}
// }}}
}
// }}}
/*
* Local variables:
* tab-width: 4
* c-basic-offset: 4
* End:
*/
?>
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