I hope someone can help me… I have a user defined function that fits the data really well, but I get the abnormal termination of minimization error message. Attached are the script as well as an example root histogram file.
StartParameters_86Kr64Ni_Z3.h (1.16 KB)
FitT.C (5.59 KB)
c.root (5.45 KB)
Hello,
your fit is basically fine, it fails due to some numerical precision problems.
Please NEVER USE SINGLE PRECISION for performing complex numerical
calculations like in your fitting function. When fitting, you must use always
double precision. Using mixed float-double precision is also a bad idea, because it slows down the calculations on 64 bit architectures.
Changing in your function from Float_t to Double_t your fit will converge fine
Best Regards
Lorenzo