com.jidesoft.chart.fit
Class QuadraticFitter

java.lang.Object
  com.jidesoft.chart.fit.QuadraticFitter

All Implemented Interfaces:

CurveFitter

public class QuadraticFitter
extends Object
implements CurveFitter

A class that fits a quadratic polynomial curve to a set of points contained in a ChartModel

Method Summary

DefaultChartModel	createModel(Polynomial polynomial, Range<?> xRange, int numPoints)
AnnotatedChartModel	createModel(String name, Polynomial polynomial, Double[] xs) Sometimes you want a generated model to have exactly the same coordinates on the x axis as the original model.
DefaultChartModel	createModel(String name, Polynomial polynomial, Range<?> xRange, int numPoints)
static QuadraticFitter	getInstance() Returns an instance of a QuadraticFitter.
Polynomial	performRegression(ChartModel model) Start by creating a RealMatrix to store the coefficients double[][] coefficientsData = {{2, 3, -2}, {-1, 7, 6}, {4, -3, -5}}; RealMatrix coefficients = new RealMatrixImpl(coefficientsData); Next create a double[] array to represent the constant vector and use solve(double[]) to solve the system double[] constants = {1, -2, 1}; double[] solution = coefficients.solve(constants);
AnnotatedChartModel	performRegression(String name, ChartModel model, Range<?> xRange, int numPoints)

Methods inherited from class java.lang.Object

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

Method Detail

getInstance

public static QuadraticFitter getInstance()

Returns an instance of a QuadraticFitter. If an instance has already been created then it is returned.

Returns:

an instance of a QuadraticFitter

performRegression

public Polynomial performRegression(ChartModel model)

Start by creating a RealMatrix to store the coefficients double[][] coefficientsData = {{2, 3, -2}, {-1, 7, 6}, {4, -3, -5}}; RealMatrix coefficients = new RealMatrixImpl(coefficientsData);

Next create a double[] array to represent the constant vector and use solve(double[]) to solve the system double[] constants = {1, -2, 1}; double[] solution = coefficients.solve(constants);

Specified by:

performRegression in interface CurveFitter

Parameters:

model - the chart model over which to perform the regression

Returns:

a Polynomial as the result of the regression

createModel

public DefaultChartModel createModel(Polynomial polynomial,
                                     Range<?> xRange,
                                     int numPoints)

Specified by:

createModel in interface CurveFitter

createModel

public AnnotatedChartModel createModel(String name,
                                       Polynomial polynomial,
                                       Double[] xs)

Sometimes you want a generated model to have exactly the same coordinates on the x axis as the original model. If you pass in the coordinates as xs here, this method returns such a model.

Parameters:

name - the name of the model to be generated

polynomial - the polynomial of the curve

xs - the x coordinates in the resulting ChartModel

Returns:

the generated ChartModel

createModel

public DefaultChartModel createModel(String name,
                                     Polynomial polynomial,
                                     Range<?> xRange,
                                     int numPoints)

Specified by:

createModel in interface CurveFitter

performRegression

public AnnotatedChartModel performRegression(String name,
                                             ChartModel model,
                                             Range<?> xRange,
                                             int numPoints)

Specified by:

performRegression in interface CurveFitter