CodingForums.com - Square root script

CodingForums.com (http://www.codingforums.com/index.php)

- Post a PHP snippet (http://www.codingforums.com/forumdisplay.php?f=41)

- - Square root script (http://www.codingforums.com/showthread.php?t=175826)

Square root script

If you ever wandered how square root program might look light, like i did, well, this is how i figure it out to be. Someone could look how to make it work with float numbers. ;)

PHP Code:


		
			
<?php
function square_root($square) {
    while ($i < $square) {
        if ($i*$i == $square) {
            $square_root = $i;
        }
        $i++;
    }
    
    if (!$square_root) {
        $square_root = "Square root is not int";
    }
    return $square_root;
}

print square_root(49);
?>

Babylonian, capable of doubles:

PHP Code:


		
			
<?php

function babylonianSqrt($x, $dPrecision = 0.0000001)
{
    if ($x < 0)
    {
        throw new InvalidArgumentException('Number must be positive!');
    }
    $dGuess = 1;
    $bKeepGoing = true;
    while ($bKeepGoing)
    {
        $dOldGuess = $dGuess;
        $dGuess = ($dOldGuess + ($x / $dOldGuess)) / 2;
        if (abs(($dGuess - $dOldGuess) / $dOldGuess) <= $dPrecision)
        {
            $bKeepGoing = false;
        }
    }
    return $dGuess;
}

$dNumber = 14.34;
printf("The babylonianSqrt of %0.5f is %0.5f\n", $dNumber, babylonianSqrt($dNumber));

?>