Package org.apache.commons.math4.legacy.optim
Generally, optimizers are algorithms that will either
minimize
or
maximize
a scalar function, called the
objective
function
.
For some scalar objective functions the gradient can be computed (analytically
or numerically). Algorithms that use this knowledge are defined in the
org.apache.commons.math4.legacy.optim.nonlinear.scalar.gradient
package.
The algorithms that do not need this additional information are located in
the org.apache.commons.math4.legacy.optim.nonlinear.scalar.noderiv
package.
Some problems are solved more efficiently by algorithms that, instead of an
objective function, need access to all the observations.
Such methods are implemented in the org.apache.commons.math4.legacy.fitting
package.
This package provides common functionality for the optimization algorithms.
Abstract classes (BaseOptimizer
and
BaseMultivariateOptimizer
) contain
boilerplate code for storing evaluations
and iterations
counters and a userdefined
convergence checker
.
For each of the optimizer types, there is a special implementation that wraps an optimizer instance and provides a "multistart" feature: it calls the underlying optimizer several times with different starting points and returns the best optimum found, or all optima if so desired. This could be useful to avoid being trapped in a local extremum.

Interface Summary Interface Description ConvergenceChecker<PAIR> This interface specifies how to check if an optimization algorithm has converged.OptimizationData Marker interface.OptimizationProblem<PAIR> Common settings for all optimization problems. 
Class Summary Class Description AbstractConvergenceChecker<PAIR> Base class for all convergence checker implementations.AbstractOptimizationProblem<PAIR> Base class for implementing optimization problems.BaseMultiStartMultivariateOptimizer<PAIR> Base class multistart optimizer for a multivariate function.BaseMultivariateOptimizer<PAIR> Base class for implementing optimizers for multivariate functions.BaseOptimizer<PAIR> Base class for implementing optimizers.InitialGuess Starting point (first guess) of the optimization procedure.MaxEval Maximum number of evaluations of the function to be optimized.MaxIter Maximum number of iterations performed by an (iterative) algorithm.PointValuePair This class holds a point and the value of an objective function at that point.PointVectorValuePair This class holds a point and the vectorial value of an objective function at that point.SimpleBounds Simple optimization constraints: lower and upper bounds.SimplePointChecker<PAIR extends Pair<double[],? extends Object>> Simple implementation of theConvergenceChecker
interface using only point coordinates.SimpleValueChecker Simple implementation of theConvergenceChecker
interface using only objective function values.SimpleVectorValueChecker Simple implementation of theConvergenceChecker
interface using only objective function values.