Re: Re: Extension of MatrixExp
- To: mathgroup@smc.vnet.net
- Subject: [mg11766] Re: [mg11723] Re: [mg11669] Extension of MatrixExp
- From: "Jürgen Tischer" <jtischer@pitagoras.univalle.edu.co>
- Date: Sat, 28 Mar 1998 00:25:08 -0500
Normal is working, too:
In[1]:= MatrixExp[t m]//Normal
Out[1]= {{E^(2t), ...
J|rgen
----------
> From: David Withoff <withoff@wolfram.com>
To: mathgroup@smc.vnet.net
> To: mathgroup@smc.vnet.net
> Subject: [mg11766] [mg11723] Re: [mg11669] Extension of MatrixExp
> Date: Thursday, March 26, 1998 3:08 AM
>
> > 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
> >
> > The result is ok, but perhaps somebody have a best (more compact)
> > solution...
> >
> > Thank you for your answers.
> >
> > Fred lang
>
> Try using ToRadicals:
>
> In[1]:= m = {{2,0,0},{0,3,0},{0,0,4}} ;
>
> In[2]:= MatrixExp[t m] //ToRadicals
>
> 2 t 3 t 4 t Out[2]= {{E , 0, 0},
> {0, E , 0}, {0, 0, E }}
>
> The fact that you need to do this is an oversight in Version 3.0. This
> will almost certainly be changed for the next release of Mathematica.
>
> Dave Withoff
> Wolfram Research