hypot, hypotf, hypotl - Euclidean distance function
Math library (libm
, -lm
)
#include <math.h>
double hypot(double x, double y);
float hypotf(float x, float y);
long double hypotl(long double x, long double y);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
hypot():
_ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
|| _XOPEN_SOURCE
|| /* Since glibc 2.19: */ _DEFAULT_SOURCE
|| /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
_ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
|| /* Since glibc 2.19: */ _DEFAULT_SOURCE
|| /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
These functions return
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.
On success, these functions return the length of the hypotenuse 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.
See math_error(7) for information on how to determine whether an error has occurred when calling these functions.
The following errors can occur:
errno
is set to ERANGE. An overflow
floating-point exception (FE_OVERFLOW) is raised.
An underflow floating-point exception (FE_UNDERFLOW) is raised.
These functions do not set errno
for this case.
For an explanation of the terms used in this section, see attributes(7).
Interface | Attribute | Value |
Thread safety | MT-Safe |
C11, POSIX.1-2008.
C99, POSIX.1-2001.
The variant returning double
also conforms to SVr4,
4.3BSD.