3.5.2.5.28 Fresnel_s

Definition:

S = fresnel\_s(x) evaluates an approximation to the Fresnel Integral

S(x)=\int_0^x\sin (\frac \pi 2t^2)dt

The function is based on Chebyshev expansions.

For more information please review the s20acc function in the NAG document.

Parameters:

x (input, double)
The argument x of the function.
s (output, double)
Approximation of the Fresnel Integral.