| Name | Description | Type | Package | Framework |
| AbstractEvaluation | An implementation of LeastSquaresProblem. | Class | org.apache.commons.math3.fitting.leastsquares | Apache Commons |
| EvaluationRmsChecker | Check if an optimization has converged based on the change in computed RMS. | Class | org.apache.commons.math3.fitting.leastsquares | Apache Commons |
| GaussNewtonOptimizer | Gauss-Newton least-squares solver. | Class | org.apache.commons.math3.fitting.leastsquares | Apache Commons |
| GaussNewtonOptimizer .Decomposition | The decomposition algorithm to use to solve the normal equations. | Class | org.apache.commons.math3.fitting.leastsquares.GaussNewtonOptimizer | Apache Commons |
| LeastSquaresAdapter | An adapter that delegates to another implementation of LeastSquaresProblem. | Class | org.apache.commons.math3.fitting.leastsquares | Apache Commons |
| LeastSquaresBuilder | A mutable builder for LeastSquaresProblems. | Class | org.apache.commons.math3.fitting.leastsquares | Apache Commons |
| LeastSquaresFactory | A Factory for creating LeastSquaresProblems. | Class | org.apache.commons.math3.fitting.leastsquares | Apache Commons |
| LeastSquaresOptimizer | An algorithm that can be applied to a non-linear least squares problem. | Interface | org.apache.commons.math3.fitting.leastsquares | Apache Commons |
| LeastSquaresOptimizer .Optimum | The optimum found by the optimizer. | Interface | org.apache.commons.math3.fitting.leastsquares.LeastSquaresOptimizer | Apache Commons |
| LeastSquaresProblem | The data necessary to define a non-linear least squares problem. | Interface | org.apache.commons.math3.fitting.leastsquares | Apache Commons |
| LeastSquaresProblem .Evaluation | An evaluation of a LeastSquaresProblem at a particular point. | Interface | org.apache.commons.math3.fitting.leastsquares.LeastSquaresProblem | Apache Commons |
| LevenbergMarquardtOptimizer | This class solves a least-squares problem using the Levenberg-Marquardt This implementation should work even for over-determined systems | Class | org.apache.commons.math3.fitting.leastsquares | Apache Commons |
| MultivariateJacobianFunction | A interface for functions that compute a vector of values and can compute their derivatives (Jacobian). | Interface | org.apache.commons.math3.fitting.leastsquares | Apache Commons |
| ParameterValidator | Interface for validating a set of model parameters. | Interface | org.apache.commons.math3.fitting.leastsquares | Apache Commons |
| ValueAndJacobianFunction | A interface for functions that compute a vector of values and can compute their derivatives (Jacobian). | Interface | org.apache.commons.math3.fitting.leastsquares | Apache Commons |