constrained nonlinear optimization

[Alain_S]

Dear,

Using the "Constrained nonlinear optimization" vi (click) I sometimes get the error -20071 "The input matrix is not positive definite".

What can I do about it?

Thanks for any advice!

[MHoffmann]

Hi,

there is already a bug reported for this issue if all coordinate at the start terminal are zero. A workaround is by wiring non-zero coordinates to the start terminal. A permanent solution is predicted for LV 2014.

Regards,

Michael

[Alain_S]

Please find attached a sample vi (LV 8.6) containing 2 data sets.

One of them with error, the other not.

[Alain_S]

Hi Michael,

Thanks for the reply but I never use zero as start coordinates.

So if there is a bug there I never wake it up

As you will see in the example vi I posted I try to calculate the minimum zone circle of the given data set.
As start I uses:

X and Y result of the "Fitting on a sphere" vi

minimum radius is half the smallest radius in the data set

maximum radius is 1.5 times the largest radius in the data set

(Please note that I excluded those calculation sfrom the test vi!)

So I'm pretty sure I never have all start data set to 0.

Best regards