The expint(x) function computes the exponential integral of x.

The expint(M) function computes the element-wise exponential integral of M.  The result, R, is formed as R[i,j] = expint(M[i,j]).

$\mathrm{with}\left(\mathrm{MTM}\right)\:$

$M≔⟨⟨7.117324\,7.792180⟩\left|⟨-6.816817\,5.407879⟩\right|⟨3.484225\,-7.384283⟩|⟨5.010275\,2.681853⟩⟩$

$M≔\left[\begin{array}{cccc}7.117324& \mathrm{-6.816817}& 3.484225& 5.010275\\ 7.792180& 5.407879& \mathrm{-7.384283}& 2.681853\end{array}\right]$

$\mathrm{expint}\left(M\right)$

$\left[\begin{array}{cccc}0.0001011777767& \mathrm{-164.9435469}-3.141592654\mathrm{I}& 0.007107633866& 0.001134534114\\ 0.00004748425685& 0.0007132450949& \mathrm{-262.8444112}-3.141592654\mathrm{I}& 0.01963923428\end{array}\right]$