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



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():
           _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
       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
       On success, these functions return the length of a right-angled  trian-
       gle 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.

ATTRIBUTES
       For   an   explanation   of   the  terms  used  in  this  section,  see
       attributes(7).

       allbox; lbw27 lb lb  l  l  l.   Interface Attribute Value  T{  hypot(),
       hypotf(), hypotl() T}   Thread safety  MT-Safe


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

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

SEE ALSO
       cabs(3), sqrt(3)

COLOPHON
       This  page  is  part of release 4.16 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
       https://www.kernel.org/doc/man-pages/.



                                  2017-09-15                          HYPOT(3)