MnMigrad segmentation fault


I have a short question to the Minuit2 minimization package. I am trying to use the MIGRAD routine but after one step it gives me an error message of “segmentation fault”. Now I checked MnScan and that works very well and runs without an error message. So does the MnSimplex. Now when change to MIGRAD I get an error message of segmentation fault. The function is kind of big and it has 18 parameters but all of them enter the minimization with limits specified through MnUserParameters. I run it through terminal as c++ script. Everything seems to work but not migrad. What is the maximum allowed numbers of parameters in MIGRAD?



There is no hard coded limit on the number of parameters, only the memory. We have been doing minimisations with 1000 and more parameters so, 18 is not certainly a problem.

I would need to look and possibly run your code to understand the problem. Please post it, with all that is needed to run, so we can investigate it

Best Regards


Thanks for the prompt reply!
wow 1000 parameters that sound like a fun mathematical problem. :slight_smile:
My problem is nowhere near that complicated but my code is in bits and pieces so I am not sure I can send it to you this prompt. First I’ll try to debug myself I was just curious whether there is a limit or not on the number of parameters to be fitted and there isn’t! That is good news!

Thanks again!