hexdec
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)))
...
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).
Parameters
-
x -
Length of first side
-
y -
Length of second side
Return Values
Calculated length of the hypotenuse
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User Contributed Notes
hypot
</Life>.org
09-Aug-2006 09:56
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 03:18
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.
?>