Crate exponential_integral

The exponential integral, often written $\text{Ei}$, equal to the the integral of an exponentiated input over the input itself: $\text{Ei}(t) = \int_{-\infty}^{t} \frac{ e^{u} }{ u } \text{d}u$

Inspired by GSL’s implementation.

Modules

• chebyshev
  Chebyshev series/polynomial approximation.
• neg
  Inputs less than 0.
• pos
  Inputs greater than 0.

Structs

• Approx
  An approximate value alongside an estimate of its own approximation error.

Enums

• Error
  An approximate value alongside an estimate of its own approximation error.

Functions

• E1
  Original C code
• Ei
  Original C code