Levenberg-Marquardt - termination?

[battler.]

[Darin.K]

I found the analytic expression for the different partial derivatives and then estimate the infinite sum in the same fashion as for f(x).  I use different while loops because there is no guarantee that any of the new series will converge in the same number of terms as f(x).  I'll try to find the scratch paper where I wrote the derivatives out.

[battler.]

Thanks Darin.

That would be great if you could scan the working for determining the analytical expressions for partial derivatives.

Aren't there three(3) expressions needed: dp/dp1, dp/dh and dp/dk

Do I see only two in your VI?

Then back to basics:

How does providing the partial derivatives, as you have done, help me in finding a solution (in line with what altenbach was talking about)?

[battler.]

Darin, when I replace my old function (no partial derivatives) with your one I notice:

- no of function calls is less than 10 (riduculously low in comparison).

- returns error

Error -20068 occurred at NI_Gmath.lvlib:LM get new coefficients.vi:1

Possible reason(s):

Analysis:  Input parameters has at least one element that is Inf, NaN, DBL_MAX, or DBL_MIN

[battler.]

Darin, nevermind abou my previous post.

I realised the order of the parameters which you used was different to mine.  This fixed the error.

It would be great if you could provide the partial derivatives derivation.

[battler.]

Darin!

Those partial derivative derivations would be a life-saver!