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Last updated: Fri, 26 Jan 2007

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# hypot

(PHP 4 >= 4.1.0, PHP 5)

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

## 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)`.

add a note User Contributed Notes
hypot
</Life>.org
10-Aug-2006 02:56
`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 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.
?>`
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is_finite hexdec

Last updated: Fri, 26 Jan 2007
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