Both class methods are static; you do not need to instantiate an object.
The static method toNumeral does exactly this.
It can be used for numbers from 1 to
5 999 999.
Using it to convert higher numbers works, but does not produce historically
correct results.
The second parameter $uppercase determines if the letters
should be UPPERCASE (default) or not.
Parameter number 3 sets if HTML code for overscores shall be generated;
this is necessary for numbers greater than 3999. If the parameter is set to
false, letters will be prefixed with an underscore _.
Converting Arabic numbers to Roman numerals
<?php
require_once 'Numbers/Roman.php';
echo Numbers_Roman::toNumeral(23);
//returns: XXIII
echo Numbers_Roman::toNumeral(23, false);
//returns: xxiii
?>