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2.3 Nonderivative Methods

Minimization methods that incorporate only function values generally involve some systematic method to search the conformational space. Although they are generally easy to implement, their realized convergence properties are rather poor. They may work well in special cases when the function is quite random in character or the variables are essentially uncorrelated. In general, the computational cost, dominated by the number of function evaluations, can be excessively high for functions of many variables and can far outweigh the benefit of avoiding derivative calculations. The techniques briefly sketched below are thus more interesting from a historical perspective.