erf(3M) — sys5



ERF(3M)         DOMAIN/IX Reference Manual (SYS5)         ERF(3M)



NAME
     erf, erfc - error function and complementary error function

USAGE
     #include <math.h>

     double erf (x)
     double x;

     double erfc (x)
     double x;

DESCRIPTION
                                                        x   2
                                                      2   -t
     Erf returns the error function of x, defined as ---^e   dt.
                                                       -
                                                     \|J0

     Erfc, which returns 1.0 - erf(x), is provided, because when
     erf(x) is called for large x and the result subtracted from
     1.0, a great deal of accuracy is lost (e.g., for x = 5, 12
     places are lost).

RELATED INFORMATION
     exp(3M).
































Printed 6/4/85                                              ERF-1
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