(DM42) Matrix exponential

[Gjermund Skailand]

Dear Gil,
Short answer:
there is a nice article
"Nineteen dubious ways to calcate the exponential of a matrix, tventyfive years later."

Longer answer, mostly incorrect
your method for nxn matrix is a bit like solving a n-degree equation, then exponention, and final back multiplication.
In the middle step, for unsymmetric matrixes you may end up taking the square root of negative numbers, resulting in imaginary result.

Hope this helps
best regards
Gjermund