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Hemodynamics and Biotransport Problem

spd2-disabled
Newbie

Hemodynamics and Biotransport Problem

To Whom it May Concern,

I have been getting an error while trying to use the differential solver rkfixed. The error is that a number larger than 10^306 has been calculated. I have double checked my equations but cannot find any errors. I was wondering if any one out there might be able to get this function to work properly.
4 REPLIES 4

Hemodynamics and Biotransport Problem

Switch 'rkfixed' to 'Rkadapt', and it provides a solution.

With 'rkfixed', the 2000 points you asked for resulted in time steps too large to propagate the solution. Using 'Rkadapt' allows the program to adjust the stepsize as it goes.

As an aside, and without knowing anything about the equations you're trying to solve, I looked at the solution to all the variables. I noticed a very strange behavior in your x10 variable: it dropped from its initial value of 2x10^4 down to 6.9 by the very next point, supposedly 15 seconds later. Is that consistent with what you expect?

- Guy

Hemodynamics and Biotransport Problem

I haven't looked through the worksheet yet, but as a quick check Rkadapt seems to give a solution.

Stuart

Hemodynamics and Biotransport Problem

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Hemodynamics and Biotransport Problem

Nice to see you found your way here..


btw, you might want to delete your posting below, since it looks like you uploaded 10 copies of the same file.


TTFN,
Eden
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