Computes the positive difference between two floating-point numbers.
#include <math.h> double fdim (x, y) double x; double y; float fdimf (x, y) float x; float y; long double fdiml (x, y) long double x; long double y;
The fdim, fdimf, and fdiml subroutines 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.
An application wishing to check for error situations should set the errno global variable to zero and call feclearexcept(FE_ALL_EXCEPT) before calling these subroutyines. Upon return, if errno is nonzero or fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is nonzero, an error has occurred.
| x | Specifies the value to be computed. |
| y | Specifies the value to be computed. |
Upon successful completion, the fdim, fdimf, and fdiml subroutines return the positive difference value.
If x-y is positive and overflows, a range error occurs and the fdim, fdimf, and fdiml subroutines return the value of the macro HUGE_VAL, HUGE_VALF, and HUGE_VALL, respectively.
If x-y is positive and underflows, a range error may occur, and 0.0 is returned.
If x or y is NaN, a NaN is returned.
feclearexcept Subroutine, fetestexcept Subroutine, fmax, fmaxf, or fmaxl Subroutine, and madd, msub, mult, mdiv, pow, gcd, invert, rpow, msqrt, mcmp, move, min, omin, fmin, m_in, mout, omout, fmout, m_out, sdiv, or itom Subroutine.
math.h in AIX 5L Version 5.2 Files Reference.