Tribblix: manual page: hypot.3m

HYPOT(3M) Mathematical Library Functions HYPOT(3M)

NAME

hypot, hypotf, hypotl - Euclidean distance function

SYNOPSIS

c99 [ flag... ] file... -lm [ library... ]
#include <math.h>

double hypot(double x, double y);

float hypotf(float x, float y);

long double hypotl(long double x, long double y);

DESCRIPTION

These functions compute the length of the square root of x^2 + y^2
without undue overflow or underflow.

RETURN VALUES

Upon successful completion, these functions return the length of the
hypotenuse of a right angled triangle with sides of length x^2 and
y^2.

If the correct value would cause overflow, a range error occurs and
hypot(), hypotf(), and hypotl() return the value of the macro
HUGE_VAL, HUGE_VALF, and HUGE_VALL, respectively.

If x or y is +-Inf, +Inf is returned even if one of x or y is NaN.

If x or y is NaN and the other is not +-Inf, a NaN is returned.

ERRORS

These functions will fail if:

Range Error
The result overflows.

If the integer expression (math_errhandling &
MATH_ERREXCEPT) is non-zero, the overflow floating-
point exception is raised.

USAGE

hypot(x,y), hypot(y,x), and hypot(x, -y) are equivalent.

hypot(x, +-0) is equivalent to fabs(x).

These functions takes precautions against underflow and overflow
during intermediate steps of the computation.

An application wanting to check for exceptions should call
feclearexcept(FE_ALL_EXCEPT) before calling these functions. On
return, if fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW |
FE_UNDERFLOW) is non-zero, an exception has been raised. An
application should either examine the return value or check the
floating point exception flags to detect exceptions.

ATTRIBUTES