Hi,
in general if it is just a warning it is fine, if then Minuit converges correctly, i.e. no convergence error is reported. Otherwise, which message do you get ? I would need to see your output log messages,
yes the minimum is not valid (you have a large edm value = 82318.7 ), so
you can’t trust the result.
Did you have any other message before to know why the minimization stopped ?
Lorenzo
I suspect you got stack in settle point, or due to a problem in your function evaluation, in a region where the function does not change its value, and this point is not the minimum.
I will check carefully your objective function evaluation and look at all the function value during the iteration process.
Again, I would need the full debug information for helping you. A program reproducing this will help
Looking at the MINUIT manual , I suspect the same as you pointed out.
I run this program in CMSSW framework, the simulation and reconstruction package for CMS experiment and integrated with some other codes.
So please let me know what is the best way I can provide you this program.
If you just want to take a look of the program I can keep the relevant file it in my public area.
I can also provide you the function values for the iterations for such a case.
Please let me know.
(Just thinking if any kind of discontinuity in the function could leads to such situation???)
Thanks for the file. The function seems oscillating around the minimum, better value were found before. I think this is due to the problem in the derivative calculation due to discontinuities in the function.
If you can keep the function continous there is no much more we can do.
I would try to run maybe Simplex or another minimizer like the simulated annealing (it is provided by mathmore) to see if better minimum values are found. They do not rely on the derivative calculations to find the minimum.
I have prepared a small script to produce the same result for the function I am using. Although I could not able to check it because I am not able to provide the function correctly to MIGRAD and also it complains about a missing symbol!
I will highly appreciate if you could look into this small script. I have also put a file “log_problem” which is from running my original code in CMSSW and gives the debug info. for invalid minimum.