[ADOL-C] Performance dilemma

[Antoine De Blois]

Hi Everyone,

I would like to know which of the 2 following options is computationally better. My current version of the code involves surface areas as independent variables. I now have to add the volumes to the independent variable, which leads to a dilemma for my implementation. In my application, surfaces and volumes are pre-computed on the entire computational domain. However, I perform automatic differentiation on a smaller stencil. The only thing to remember for you is that the surfaces and volumes are already pre-computed on the entire grid.

Since the surfaces and volumes are in fact dependent on the coordinates S=S(X,Y,Z), V=V(X,Y,Z), should I:


1.       Use the coordinates as independent variables (Xa << X; Ya << Y; Za <<Z;) and then compute the surfaces and volumes as active arrays

2.       Use the surfaces and volumes as independent variables (Sa <<S; Va <<V;), yielding more independent variables, but less computation between the trace_on and trace_off.

I already asked what was the biggest contributing factor for efficient process was the amount of computation between the trace_on and trace_off, and not the amount of indendent variables. This would lead to option 2, right, especially that the volumes calculation involves tests at the boundaries.

Thank you for your time,
Cheers,
Antoine


Antoine DeBlois
Specialiste ingenierie, MDO lead / Engineering Specialist, MDO lead
Aéronautique / Aerospace
T    514-855-5001, x 50862
antoine.deblois at aero.bombardier.com<mailto:antoine.deblois at aero.bombardier.com>

2351 Blvd Alfred-Nobel
Montreal, Qc
H4S 1A9

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