src.Math.Special.E2

src.Math.Special.E2(*args, **kwargs)

Calculate Exponential integral \(E_2(x)\) from \(E_1(x)\).

Parameters

x (np.double or array-like) – independent variable x

Returns

E2 – 2nd order Exponential integral of x

Return type

np.double or array-like

Notes

Using relation 1 Equation(11.127):

\[E_{n+1}(x) = [e^{-x} - xE_{n}(x)] / n\]

References

1

Ivan Hubeny, Dimitri Mihalas, “Theory of Stellar Atmosphere: An Introduction to Astrophysical Non-equilibrium Quantitative Spectroscopic Analysis”, Princeton University Press, pp. 365, 2015.