Error 1 occurred at Armijo rule stepsize reduction failed to reduce function value within maxiters

[TKlostermann]

Hi,

I am trying to use the unconstrained optimization VI to fit a measured Spectrum. However, on each call of the Vi I get the error:

      Error 1 occurred at Armijo rule stepsize reduction failed to reduce function value within maxiters

      Possible reason(s):

      LabVIEW:  An input parameter is invalid. For example if the input is a path, the path might contain a character not allowed by the OS such as ? or  @.
     =========================
     NI-488:  Command requires GPIB Controller to be Controller in Charge.

Does anybody know what I am doing wrong and how I can fix it?

The VI for the Armijo rule stepsize reduction can be found here:

<labviewPath>\vi.lib\gmath\NumericalOptimization\qn_armijo rule stepsize reduction.vi

In the current implementation, the Spectrum is fit to a rectangular Spectrum. Can this be the cause for the error?

I have attached the VIs I am using. They are written in LabVIEW 2010.

[OEMa]

Hi TKlostermann,

could you be a bit more precize about your error? I can't get it.

At which exact step do you get the error? Could you give us a project with some data in which we can reproduce the error?

[TKlostermann · Accepted solution]

Thank you Marc67 for your quick reply, but I found the error.

It was rather stupid, I used a bad starting vector for the Unconstrained Optimization VI, which had too low values.