erfc

Computes the complementary error function at x, equal to 1 - erf(x).

The complementary form is useful when erf(x) is close to 1, since computing 1 - erf(x) directly would lose precision. Computed via regularizedGammaQ for the positive branch.

Example:

erfc(0.0) // 1.0
erfc(2.0) // 0.0046... (the tail probability)
erf(2.0) + erfc(2.0) // 1.0

Return

the complementary error function value at x, in the range 0, 2.

Parameters

x

the point at which to evaluate.