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Last updated: Fri, 14 Aug 2009

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hypot

(PHP 4 >= 4.1.0, PHP 5)

hypotCalcul la longueur de l'hypoténuse d'un triangle à angle droit

Description

float hypot ( float $x , float $y )

hypot() retourne la longueur de l'hypoténuse d'un triangle à angle droit qui a des cotés d'une longueur x et y ou bien la distance du point (x , y ) depuis l'origine. Ceci est l'équivalent de sqrt(x*x + y*y).

Liste de paramètres

x

Longueur du premier côté

y

Longueur du second côté

Valeurs de retour

La longueur calculée de l'hypoténuse



is_finite> <hexdec
Last updated: Fri, 14 Aug 2009
 
add a note add a note User Contributed Notes
hypot
</Life>.org
10-Aug-2006 09:56
to robinv at ecosse dot net:

hypo(a, b, c) === hypo(a, hypo(b, c))
hypo(a, b, c, d) === hypo(a, hypo(b, hypo(c, d)))
...
R. Victor Klassen
24-Jun-2005 03:03
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 05:18
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.

?>

is_finite> <hexdec
Last updated: Fri, 14 Aug 2009
 
 
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