erfc, erfcf, erfcl, erfcd32, erfcd64, and erfcd128 Subroutines

Purpose

Computes the complementary error function.

Syntax

#include <math.h>

float erfcf (x)
float x;

long double erfcl (x)
long double x;

double erfc (x)
double x;
_Decimal32 erfcd32 (x)
_Decimal32 x;
_Decimal64 erfcd64 (x)
_Decimal64 x;

_Decimal128 erfcd128 (x)
_Decimal128 x;

Description

The erfcf, erfcl, erfc, erfcd32, erfcd64, and erfcd128 subroutines compute the complementary error function 1.0 - erf(x).

An application wishing to check for error situations should set errno to zero and call feclearexcept(FE_ALL_EXCEPT) before calling these functions. Upon return, if errno is nonzero or fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is nonzero, an error has occurred.

Parameters

Return Values

Upon successful completion, the erfcf, erfcl, erfc, erfcd32, erfcd64, and erfcd128 subroutines return the value of the complementary error function.

If the correct value would cause underflow and is not representable, a range error may occur. Either 0.0 (if representable), or an implementation-defined value is returned.

If x is NaN, a NaN is returned.

If x is ±0, +1 is returned.

If x is -Inf, +2 is returned.

If x is +Inf, +0 is returned.

If the correct value would cause underflow and is representable, a range error may occur and the correct value is returned.