_ROOT Version: 6.14
Compiler: Not Provided
I am trying to do a chi-square minimization using TMinuit for 2 parameters. But I am continuously getting incorrect value of my
FCN (chi^2) which is way off from the expected value. Also, I am keep on getting an error warning in HESSE that my error matrix is not POS-DEF. (I know this might be because of the fact that my parameters are correlated but I have checked it so many times and they are not correlated to each other). Since it’s just two parameters, I tried to write a small minimization routine of my own to see if there is some problem in my function but my minimization routine is working just fine with the same function that I am using in TMinuit. The reason for using TMinuit is because eventually I want to use 4 fit parameters on the same function and my minimization routine would be very inefficient.