Function lattice_qcd_rs::su3::su3_exp_i

pub fn su3_exp_i(su3_adj: Su3Adjoint) -> CMatrix3

give the SU3 matrix from the adjoint rep, i.e compute exp(i v^a T^a )

The algorithm use is much more efficient the diagonalization method. It use the Cayley–Hamilton theorem. If you wish to find more about it you can read the OpenQCD documentation that can be found here or by downloading a release. Note that the documentation above explain the algorithm for exp(X) here it is a modified version for exp(i X).