Re: matrix diffential equations
- To: mathgroup at smc.vnet.net
- Subject: [mg27540] Re: [mg27510] matrix diffential equations
- From: Tomas Garza <tgarza01 at prodigy.net.mx>
- Date: Sat, 3 Mar 2001 03:40:25 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
Whatever it is you're trying to accomplish with that definition, it
didn't crash Mathematica in my machine (Windows 98). I just aborted it
with Alt-. after a few seconds and that was that.
In[1]:=
y := Array[y, {3, 3}]
In[2]:=
y
$RecursionLimit::"reclim": "Recursion depth of \!\(256\) exceeded."
$RecursionLimit::"reclim": "Recursion depth of \!\(256\) exceeded."
$RecursionLimit::"reclim": "Recursion depth of \!\(256\) exceeded."
General::"stop": "Further output of \!\($RecursionLimit :: \"reclim\"\)
will \
be suppressed during this calculation."
Out[2]=
$Aborted
Now, in your question I think there is something missing, when you say y
:= Array[ytmp, {3, 3}], and then use y[u], y[s] and y'[u]. Perhaps you
could clarify what is ytmp.
Tomas Garza
Mexico City
Martin Richter wrote:
> Simple way to crash Mathematica is by writing
> y := Array[y, {3, 3}]
> Even Quit Kernel doesn't stop Mathematica, and I have experience
application
> error and crashes (both in Mathematica dll and Mathematica.exe for
simple
> programs) and in so cases Mathematica has to be closed from the Task
Manager
> (Windows 2000). Regarding Mathematica exception coding, I'm not
impressed,
> just IMHO.
>
> Just have to buss it out :-(
>
> My question is the following: Is there a simple way to define matrix
> diffential equation in Mathematica, I have tried something like:
> A[t_]:= {{1,1,1},{1,1,1},{1,1,1}}*t
> y := Array[ytmp, {3, 3}]
> eqns = {y'[u] == A[u]. y[u], y[s] == A[s]}
> NDSolve[eqns, y, {u, s, t}]
>
> But this is not the way.
>
> TIA
> Martin