Hi Mauro, I don't know exactly what the 'sum path # # # # ' in Artemis is supposed to display, but I'd guess that some variable or fit parameter is being unstable.
I've already posted this issue in a post dated 2006/10/04 and Bruce asked to me to give him something to reproduce this issue on his computer but this behavior is very unstable and I don't understand how to exactly reproduce it.
I think we'd need to see a project that could be made to have this problem, even if it happens only occasionally.
I would like to know in your opinion what could bring a variable during the minimization process to NAN.
Divide-by-zero and log(-1) come to mind, but I think we'd need to determine whether a variable is being brought to NAN by the minimization process before speculating why. Cheers, --Matt