To view the default settings do one of the following:

• go to the Fitting menu and click Edit... Advanced Options
• click the Advanced Options icon  in the Fitting toolbar.

The list of defaults is given below, click on the links for further information:

Fitting Algorithms:          Levenberg-Marquardt

Tolerance:                       1e-4

Solver Algorithms:          Rosenbrock

Solver accuracy:              1e-3

Max Iterations:                400

Automatic Restarts:        On

These defaults were chosen to provide users with robust settings that will work on most problems.

The Levenberg-Marquardt method is efficient, but requires more runs of the solver per iteration than the Simplex method. It uses the local sensitivity (gradient) of the SSQ function to the parameter values to find the best fit.