erf(3M)                                                   erf(3M)



     NAME
          erf, erfc - error function and complementary error function

     SYNOPSIS
          #include <math.h>

          double erf (x)
          double x;

          double erfc (x)
          double x;

     DESCRIPTION                                            x
          erf returns the error function of x, defined as _2 e-t2dt.
                                                          \|0
          erfc, which returns 1.0 - erf(x), is provided because of the
          extreme loss of relative accuracy if erf(x) is called for
          large x and the result subtracted from 1.0 (e.g. for x = 5,
          12 places are lost).

     SEE ALSO
          exp(3M).

































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