org.apache.commons.math3.fitting

Class SimpleCurveFitter

java.lang.Object

org.apache.commons.math3.fitting.AbstractCurveFitter

org.apache.commons.math3.fitting.SimpleCurveFitter

public class SimpleCurveFitter
extends AbstractCurveFitter

Fits points to a user-defined function.

Since:

3.4

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.commons.math3.fitting.AbstractCurveFitter

AbstractCurveFitter.TheoreticalValuesFunction

Field Summary

Fields

Modifier and Type	Field and Description
private ParametricUnivariateFunction	function Function to fit.
private double[]	initialGuess Initial guess for the parameters.
private int	maxIter Maximum number of iterations of the optimization algorithm.

Constructor Summary

Constructors

Modifier	Constructor and Description
private	SimpleCurveFitter(ParametricUnivariateFunction function, double[] initialGuess, int maxIter) Contructor used by the factory methods.

Method Summary

Methods

Modifier and Type	Method and Description
static SimpleCurveFitter	create(ParametricUnivariateFunction f, double[] start) Creates a curve fitter.
protected LeastSquaresProblem	getProblem(java.util.Collection<WeightedObservedPoint> observations) Creates a least squares problem corresponding to the appropriate curve.
SimpleCurveFitter	withMaxIterations(int newMaxIter) Configure the maximum number of iterations.
SimpleCurveFitter	withStartPoint(double[] newStart) Configure the start point (initial guess).

Methods inherited from class org.apache.commons.math3.fitting.AbstractCurveFitter

fit, getOptimizer

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

function

private final ParametricUnivariateFunction function

Function to fit.

initialGuess

private final double[] initialGuess

Initial guess for the parameters.

maxIter

private final int maxIter

Maximum number of iterations of the optimization algorithm.

Constructor Detail

SimpleCurveFitter

private SimpleCurveFitter(ParametricUnivariateFunction function,
                 double[] initialGuess,
                 int maxIter)

Contructor used by the factory methods.

Parameters:

function - Function to fit.

initialGuess - Initial guess. Cannot be null. Its length must be consistent with the number of parameters of the function to fit.

maxIter - Maximum number of iterations of the optimization algorithm.

Method Detail

create

public static SimpleCurveFitter create(ParametricUnivariateFunction f,
                       double[] start)

Creates a curve fitter. The maximum number of iterations of the optimization algorithm is set to Integer.MAX_VALUE.

Parameters:

f - Function to fit.

start - Initial guess for the parameters. Cannot be null. Its length must be consistent with the number of parameters of the function to fit.

Returns:

a curve fitter.

See Also:

withStartPoint(double[]), withMaxIterations(int)

withStartPoint

public SimpleCurveFitter withStartPoint(double[] newStart)

Configure the start point (initial guess).

Parameters:

newStart - new start point (initial guess)

Returns:

a new instance.

withMaxIterations

public SimpleCurveFitter withMaxIterations(int newMaxIter)

Configure the maximum number of iterations.

Parameters:

newMaxIter - maximum number of iterations

Returns:

a new instance.

getProblem

protected LeastSquaresProblem getProblem(java.util.Collection<WeightedObservedPoint> observations)

Creates a least squares problem corresponding to the appropriate curve.

Specified by:

getProblem in class AbstractCurveFitter

Parameters:

observations - Sample points.

Returns:

the least squares problem to use for fitting the curve to the given points.