HYPOT
Section: Linux Programmer's Manual (3)
Updated: 2008-08-05
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NAME
hypot, hypotf, hypotl - Euclidean distance function
SYNOPSIS
#include <math.h>
double hypot(double x, double y);
float hypotf(float x, float y);
long double hypotl(long double x, long double y);
Link with -lm.
Feature Test Macro Requirements for glibc (see
feature_test_macros(7)):
hypot():
_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE || _ISOC99_SOURCE; or
cc -std=c99
hypotf(),
hypotl():
_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE; or
cc -std=c99
DESCRIPTION
The
hypot()
function returns
sqrt(x*x+y*y).
This is the length of the hypotenuse of a right-angled triangle
with sides of length
x
and
y,
or the distance of the point
(x,y)
from the origin.
The calculation is performed without undue overflow or underflow
during the intermediate steps of the calculation.
RETURN VALUE
On success, these functions return the length of a right-angled triangle
with sides of length
x
and
y.
If
x
or
y
is an infinity,
positive infinity is returned.
If
x
or
y
is a NaN,
and the other argument is not an infinity,
a NaN is returned.
If the result overflows,
a range error occurs,
and the functions return
HUGE_VAL,
HUGE_VALF,
or
HUGE_VALL,
respectively.
If both arguments are subnormal, and the result is subnormal,
a range error occurs,
and the correct result is returned.
ERRORS
See
math_error(7)
for information on how to determine whether an error has occurred
when calling these functions.
The following errors can occur:
- Range error: result overflow
-
errno
is set to
ERANGE.
An overflow floating-point exception
(FE_OVERFLOW)
is raised.
- Range error: result underflow
-
An underflow floating-point exception
(FE_UNDERFLOW)
is raised.
-
These functions do not set
errno
for this case.
CONFORMING TO
C99, POSIX.1-2001.
The variant returning
double
also conforms to
SVr4, 4.3BSD.
SEE ALSO
cabs(3),
sqrt(3)
COLOPHON
This page is part of release 3.22 of the Linux
man-pages
project.
A description of the project,
and information about reporting bugs,
can be found at
http://www.kernel.org/doc/man-pages/.