Tribblix: manual page: fdim.3m

FDIM(3M) Mathematical Library Functions FDIM(3M)

NAME

fdim, fdimf, fdiml - compute positive difference between two
floating-point numbers

SYNOPSIS

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

double fdim(double x, double y);

float fdimf(float x, float y);

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

DESCRIPTION

These functions determine the positive difference between their
arguments. If x is greater than y, x-y is returned. If x is less than
or equal to y, +0 is returned.

RETURN VALUES

Upon successful completion, these functions return the positive
difference value.

If x-y is positive and overflows, a range error occurs and fdim(),
fdimf(), and fdiml() returns the value of the macro HUGE_VAL,
HUGE_VALF, and HUGE_VALL, respectively.

If x or y is NaN, 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 will be raised.

USAGE

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