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erfcx

The input parameter is a real number.

Interface Definition

C interface:

float erfcxf(float x);

double erfcx(double x);

Parameters

Parameter

Type

Description

Input/Output

x

  • For erfcxf, x is of single-precision floating-point type.
  • For erfcx, x is of double-precision floating-point type.

Floating-point value of the input data.

Input

Return Value

  • The error function computing result y of the input parameter x is returned. y ∈ [–1, +1]
  • If the input is NaN, the return value is NaN.
  • If the input is +∞, the return value is 0.
  • If the input is –∞, the return value is inf.
  • For the float interface, if x ≤ –0x1.2c3cbep3, the return value is inf.
  • For the double interface, if x ≤ –0x1.aa0f4d2e063cfp4, the return value is inf.

Dependency

C: "km.h"

Example

C interface:
    // print result
    printf("erfcx(0.0) = %.15f\n",erfcx(0.0));
    printf("erfcx(-0.0) = %.15f\n",erfcx(-0.0));
    printf("erfcx(0.25) = %.15f\n",erfcx(0.25));
    printf("erfcx(-0.25) = %.15f\n",erfcx(-0.25));
    printf("erfcx(0.5) = %.15f\n",erfcx(0.5));
    printf("erfcx(-0.5) = %.15f\n",erfcx(-0.5));
    printf("erfcx(1.0) = %.15f\n",erfcx(1.0));
    printf("erfcx(-1.0) = %.15f\n",erfcx(-1.0));
    printf("erfcx(2.0) = %.15f\n",erfcx(2.0));
    printf("erfcx(-2.0) = %.15f\n",erfcx(-2.0));
    printf("erfcx(INFINITY) = %.15f\n",erfcx(INFINITY));
    printf("erfcx(-INFINITY) = %.15f\n",erfcx(-INFINITY));
    printf("erfcx(NAN) = %.15f\n",erfcx(NAN));
    printf("erfcx(-NAN) = %.15f\n",erfcx(-NAN));
    /* 
     * erfcx(0.0) = 1.000000000000000
     * erfcx(-0.0) = 1.000000000000000
     * erfcx(0.25) = 0.770346547730997
     * erfcx(-0.25) = 1.358642370104722
     * erfcx(0.5) = 0.615690344192926
     * erfcx(-0.5) = 1.952360489182557
     * erfcx(1.0) = 0.427583576155807
     * erfcx(-1.0) = 5.008980080762283
     * erfcx(2.0) = 0.255395676310506
     * erfcx(-2.0) = 108.940904389977973
     * erfcx(INFINITY) = 0.000000000000000
     * erfcx(-INFINITY) = inf
     * erfcx(NAN) = nan
     * erfcx(-NAN) = -nan
     * 
     * */