e^A (*A is a matrix)

*To*: bappadit at ecn.purdue.edu, mathgroup at yoda.physics.unc.edu*Subject*: e^A (*A is a matrix)*From*: jcw at chem.ucsd.edu (John C Wheeler)*Date*: Mon, 16 Mar 92 14:43:34 -0800

Bappaditya Banerjee writes >Does anybody have a routine to do e^A where A is atleast a 4 by 4 matrix ? What about the "standard" procedure of writing A = MLM^-1 where L is the diagaonal matrix of the eigenvalues of A and M is the matrix of eigenvecors? Then exp(A) = M exp(L) M^-1, where exp(L) is, of course just the diagonal matrix with elements that are the exponentials of the eigenvalues. This reduces the problem to the "standard" one of finding eigenvalues and eigenvectors. jcw at chem.UCSD.EDU (John C Wheeler)