Re: ODE 45

[Dmitri A. Sergatskov]

On Mon, Sep 12, 2011 at 2:44 PM, dklotzkin <address@hidden> wrote:
> Greetings all,
>
> A bit of help on the ODE45 function in Octave would be appreciated.
>
> This same bit of code works fine in Matlab, but not in Octave.
>
> "
> ...
> cycletime=2*10^-10;  % 100ps in 10 Gb/s
>
>
> for i=1:30
> y0(1,3)=I1;
> %vopt =
> odeset("AbsTol",1e-3,"RelTol",1e-6,"MaxStep",2e-13,"InitialStep",2e-20)
> %(<- played with this in Octave, but no values worked;  omitted in matlab)
>
> [t y]= ode45(@nonlinearrateequations,[0 cycletime/2], y0);
>
> "
> One difference between this and the examples is that the timescale here is
> from 0 to 100X10^-10 s.
>
> Any suggestions?
>

I suspect a roundoff  error. Try to convert your code to use
picoseconds...

Dmitri.
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