expInt1 Interface
interface
public elemental module function expInt1(val) result(res)
Arguments
| Type | Intent | Optional | Attributes | Name | ||
|---|---|---|---|---|---|---|
| real(kind=rk), | intent(in) | :: | val |
Return Value real(kind=rk)
Description
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.