Extension of MatrixExp
- To: mathgroup@smc.vnet.net
- Subject: [mg11669] Extension of MatrixExp
- From: lang@einev.ch (Fred Lang)
- Date: Sat, 21 Mar 1998 18:35:07 -0500
Dear MathGroup users,
MatrixExp is not able to give me a nice answer in the following very
easy case:
In[1] = m = {{2,0,0},{0,3,0},{0,0,4}} ; (* A diagonal matrix *)
In[2] = MatrixExp[t*m]
I define my own function
In[3] = matrixExp[m_ , t_] := Module[
{e,d,i,j} ,
e = m // N // Eigenvectors // Transpose ;
i = e // Inverse ;
d = i.m.e ;
d = d*t ;
Do[ d[[j,j]] = Exp[d[[j,j]]] , {j, Length[d]}]
e.d.i
]
In[4] = matrixExp[m , t]
The result is ok, but perhaps somebody have a best (more compact)
solution...
Thank you for your answers.
Fred lang