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Re: Solving a trivial ODE with lsode?
From: 
Geraint Paul Bevan 
Subject: 
Re: Solving a trivial ODE with lsode? 
Date: 
Thu, 12 Feb 2004 15:46:01 +0000 
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Dirk Koschützki wrote on 02/12/04 12:09:
 Hello,

 I'm trying to solve a trivial ODE with octave (2.1.35) . This example is
 used just to get a feeling for octave.

 My problem is: I did not get the correct solution.

The correct solution of \int_0^{20} 2x dt" is not x^2, so your target
function 'quadrat' is not what the result of using lsode should show.
Your initial state is 0. At t=0, the derivative is 2*0=0, hence the next
~ value of the state is also 0.
Integrating a system that has no external inputs and is in a steady
state (dx/dt=x=0) will not give you a very interesting simulation.
 
Geraint Bevan
http://www.mech.gla.ac.uk/~gbevan
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