IERF 3CW "09 March 2006" "mathcw-1.00"

Table of contents


NAME

ierff, ierf, ierfl, ierfw, ierfq, ierfll, ierfdf, ierfd, ierfdl, ierfdll - inverse error function

SYNOPSIS

cc [ flags ] -I/usr/local/include file(s) -L/usr/local/lib -lmcw [ ... ]

#include <mathcw.h>

extern float ierff (float x);

extern double ierf (double x);

extern long double ierfl (long double x);

extern __float80 ierfw (__float80 x);

extern __float128 ierfq (__float128 x);

extern long_long_double ierfll (long_long_double x);

extern decimal_float ierfdf (decimal_float x);

extern decimal_double ierfd (decimal_double x);

extern decimal_long_double ierfdl (decimal_long_double x);

extern decimal_long_long_double ierfdll (decimal_long_long_double x);

NB: Functions with prototypes containing underscores in type names may be available only with certain extended compilers.


DESCRIPTION

Compute the inverse error function of x, defined by
ierf(erf(x)) = x
where
erf(x) = (2/sqrt(pi)) integral(t = 0:x) exp(-t**2) dt = 1 - erfc(x)
The value of x should be in the range [-1, +1].

RETURN VALUES

For in-range arguments, the returned value is in the range [-Infinity, +Infinity]. Otherwise, the returned value is a quiet NaN.

ERRORS

For out-of-range, Infinity, and NaN arguments, the returned value is a quiet NaN, and errno is set to EDOM.

SEE ALSO

erf(3CW), erfc(3CW), ierfc(3CW), iphi(3CW), iphic(3CW), phi(3CW), phic(3CW).