erfcx_tail_correction()

double stan::math::opencl_kernels::erfcx_tail_correction

(

double

u

)

Correction factor of the Cody (1969) third-interval rational: erfcx(x) = (INV_SQRT_PI + u * correction(u)) / x, u = 1 / x^2.

Split out so the derivative can reuse it. See erfcx_tail_derivative.

Parameters

u	inverse square of the argument, 0 <= u <= 1/16

Returns

P(u) / Q(u)

Definition at line 29 of file erfcx.hpp.