Allan and Hastings approximation of E1 exponential integral, with coefficients from routine in: Shanjie Zhang, Jianming Jin, Computation of Special Functions, Wiley, 1996, ISBN: 0-471-11963-6, LC: QA351.C45.
Type | Intent | Optional | Attributes | Name | ||
---|---|---|---|---|---|---|
real(kind=rk), | intent(in) | :: | val |