The design of the JAIDA implementation of the AIDA IFitter interface is shown in the diagram below.
As showin, the fitter brings the data and the model together, it builds an objective function based on the chosen statistical method (specified by the IFitMethod); the objective function is optimized by the selected IOptimizer. The optmization is perfomed by changing the free parameters of the original function. The result of the fit is return to the user in an IFitResult object.
Both the fit method and the optimizer can be selected when creating the fitter through the IFitFactory. For a list of the available optimizers and fit methods please refer to the JAIDA release notes.