HYPOT(3)                  Linux Programmer's Manual                 HYPOT(3)

NAME         top

       hypot, hypotf, hypotl - Euclidean distance function

SYNOPSIS         top

       #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)):

           _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
               || _XOPEN_SOURCE
               || /* Since glibc 2.19: */ _DEFAULT_SOURCE
               || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
       hypotf(), hypotl():
           _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
               || /* Since glibc 2.19: */ _DEFAULT_SOURCE
               || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

DESCRIPTION         top

       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.

RETURN VALUE         top

       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         top

       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

              These functions do not set errno for this case.

ATTRIBUTES         top

       For an explanation of the terms used in this section, see

       │Interface                   Attribute     Value   │
       │hypot(), hypotf(), hypotl() │ Thread safety │ MT-Safe │

CONFORMING TO         top

       C99, POSIX.1-2001, POSIX.1-2008.

       The variant returning double also conforms to SVr4, 4.3BSD.

SEE ALSO         top

       cabs(3), sqrt(3)

COLOPHON         top

       This page is part of release 4.07 of the Linux man-pages project.  A
       description of the project, information about reporting bugs, and the
       latest version of this page, can be found at

                                 2016-03-15                         HYPOT(3)