Click this button to go to the index for this section.

erf(3)
NAME
  erf, erfc - Error functions

LIBRARY
  Math Library (libm.a)

SYNOPSIS
  #include <math.h>

  double erf   (double x);
  float	 erff  (float  x);
  double erfc  (double x);
  float	 erfcf (float  x);

STANDARDS
  Interfaces documented on this reference page conform to industry standards
  as follows:

  erf():  XPG4

  erfc():  XPG4

  Refer to the standards(5) reference page for more information about
  industry standards and associated tags.

DESCRIPTION
  The erf() and erff() functions return the error function of x, where erf(x)
  and erff(x) equal (2/sqrt(pi)) times the area under the curve e**(-t**2)
  between 0 and x.

  The erfc() and erfcf() functions return (1.0 - erf(x)).  The erfc()
  function can result in an underflow as x gets large.