srira |
Posted - 09/24/2005 : 1:17:52 PM Origin Version (Select Help-->About Origin): 6.1 Operating System:XP Hi
I would like to know about the chi sq values.For eg, I fit a curve using NLSF with 4 parameters, so the degrees of freedom is 4. From the chi sq table, the value varies between 4.11(prob.=.25) to 17.73 (prob.=.0005).Hence reduced chi sq. (one gets from origin fitting) varies between 1.03 to 4.4325. Can this be taken as the limits for curve fitting with 4 parameters?What would be the optimum value of chi sq. one has to look for?
Sometime though there are 4 parameters, the optimization is done by fixing any 2 paramaters.Can this be taken as usage of only 2 degrees of freedom?
Thanks! |