Class PolynomialCurveFitter

java.lang.Object

org.apache.commons.math3.fitting.AbstractCurveFitter

org.apache.commons.math3.fitting.PolynomialCurveFitter

public class PolynomialCurveFitter
extends AbstractCurveFitter

Fits points to a polynomial function.
The size of the initial guess array defines the degree of the polynomial to be fitted. They must be sorted in increasing order of the polynomial's degree. The optimal values of the coefficients will be returned in the same order.

Since:

3.3

Nested Class Summary

Nested classes/interfaces inherited from class AbstractCurveFitter

AbstractCurveFitter.TheoreticalValuesFunction

Method Summary

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

Methods inherited from class AbstractCurveFitter

fit, getOptimizer

Methods inherited from class Object

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

Method Details

create

public static PolynomialCurveFitter create(int degree)

Creates a default curve fitter. Zero will be used as initial guess for the coefficients, and the maximum number of iterations of the optimization algorithm is set to Integer.MAX_VALUE.

Parameters:

degree - Degree of the polynomial to be fitted.

Returns:

a curve fitter.

See Also:

• withStartPoint(double[])
• withMaxIterations(int)

withStartPoint

public PolynomialCurveFitter withStartPoint(double[] newStart)

Configure the start point (initial guess).

Parameters:

newStart - new start point (initial guess)

Returns:

a new instance.

withMaxIterations

public PolynomialCurveFitter withMaxIterations(int newMaxIter)

Configure the maximum number of iterations.

Parameters:

newMaxIter - maximum number of iterations

Returns:

a new instance.

getProblem

protected LeastSquaresProblem getProblem(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.