Source for file ScientificDouble.php

<?php
 
# Copyright (c) 2002-2005 Cunningham & Cunningham, Inc.
# Released under the terms of the GNU General Public License version 2 or later.
#
# PHP5 translation by Luis A. Floreani <luis.floreani@gmail.com>
 
include 'PHPFIT/Comparable.php';
 
class PHPFIT_ScientificDouble implements PHPFIT_Comparable {
    protected $value = 0.0;
    protected $precsion = 0.0;
    
    function __construct($value) {
        $this->value = $value;
    }
    
    
    /**
     * @param object o 
     * @return boolean 
     */
    
    function equals($o) {
        return $this->compareTo($o) == 0;
    }
 
    /**
     * look at interface Comparable
     */
     
    public function compareTo($other) {
        $other = floatval($other);
        $diff = $this->value - $other;
        if ($diff < -$this->precision) return -1;
        if ($diff > $this->precision) return 1;
        return 0;
    }
    
    /**
     * @param string s
     * @return ScientificDouble 
     */
     
    public static function valueOf($s) {
        $result = new PHPFIT_ScientificDouble(floatval($s));
        $result->precision = self::precision($s);
        return $result;
    }
    
    /**
     * @param string s
     * @return double 
     */
    
    public static function precision($s) {
        $value = floatval($s);
        $bound = floatval(self::tweak($s));
        return abs($bound - $value);
    }
 
 
    /**
     * @param string s
     * @return string 
     */
         
    public static function tweak($s) {
        $pos = strpos(strtolower($s), 'e');
        
        if ($pos !== false) {
            $start = substr($s, 0, $pos);
            $end = substr($s, $pos);
            return self::tweak($start) . $end;
        }
        
        if (strpos($s, '.') !== false)
            return $s . "5";
        return $s . ".5";
    }
    
    public function toString() {
        return strval( $this->value );
    }
}
?>