I am doing some nonlinear curve fitting and some of the errors for my parameters do not show, i.e. I get a "--" instead of a number. Does this mean that the error is too large for these parameters?
A missing value "--" for error probably means the fit did not converge so the iterative procedure could not estimate the error on the parameter. Dependency value close to 1 indicates that the function could be overparameterized (more parameters than is necessary). When function is overparameterized it is possible for the fit to not converge and result in missing values for errors.
You may want to consider rewriting your equation or fixing some of the parameters to "known/acceptable" values.
Also try the Origin 8 version by downloading the demo, improvements have been made over time in areas such as convergence.
No Error Displayed for NonLinear Curve Fit
Posted - 07/06/2009 : 12:28:03 PM
