(PHP 4 >= 4.1.0, PHP 5, PHP 7, PHP 8)

hypot Calculate the length of the hypotenuse of a right-angle triangle


hypot(float $x, float $y): float

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).

Bağımsız Değişkenler


Length of first side


Length of second side

Dönen Değerler

Calculated length of the hypotenuse

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User Contributed Notes 2 notes

Hayley Watson
6 years ago
If you need a higher-dimensional diagonal length (norm), you can exploit the fact that sqrt(x*x+y*y+z*z) == sqrt(x*x+sqrt(y*y+z*z)). In other words hypot(x, y, z)==hypot(x, hypot(y, z)).

To be generic about it....

function norm(...$args)
array_reduce($args, 'hypot', 0);

robinv at ecosse dot net
20 years ago
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.


function hypo()
$sum = 0;
foreach (
func_get_args() as $dimension) {
if (!
is_numeric($dimension)) return -1;
$sum += pow($dimension, 2);

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.

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