PHP: hypot - Manual

Description

float hypot ( float x, float y )

hypot() returns the length of the hypotenuse of a right-angle triangle with sides of length x and y, or the distance of the point (x, y) from the origin. This is equivalent to sqrt(x*x + y*y).

hypot

R. Victor Klassen
24-Jun-2005 08:03


A correct implementation of hypot( x, y ) avoids the overflow that might otherwise happen if either x or y is large enough that when squared it would overflow, but the answer is small enough not to cause overflow.

robinv at ecosse dot net
07-Jan-2004 09:18


A simpler approach would be to allow an arbitrary number of parameters. That would allow for whatever number of dimensions you want *and* it would be backwards compatible with the current implementation.



<?php



function hypo() 

{

    $sum = 0;

    foreach (func_get_args() as $dimension) {

        if (!is_numeric($dimension)) return -1;

        $sum += pow($dimension, 2);

    }

    return sqrt($sum);

}



print hypo();          // vector in 0 dimensions, magnitude = 0.

print hypo(1);         // vector in 1 dimension,  magnitude = 1.

print hypo(3, 4);       // vector in 2 dimensions, magnitude = 5.

print hypo(2, 3, 6);     // vector in 3 dimensions, magnitude = 7.



?>