Example usage for org.apache.commons.math3.fitting SimpleCurveFitter fit

Introduction

In this page you can find the example usage for org.apache.commons.math3.fitting SimpleCurveFitter fit.

Prototype

public double[] fit(Collection<WeightedObservedPoint> points) 

Source Link

Document

Fits a curve.

Usage

From source file:heizung.Heizkurve.java

public static PolynomialFunction getPolynomialFit(List<Point> pList) {
    PolynomialFunction result = null;/*from w  ww  .j a  va  2 s . co  m*/
    if (pList == null) {
        return result;
    }
    try {

        final WeightedObservedPoints obs = new WeightedObservedPoints();
        for (Point p : pList) {
            obs.add(p.getX(), p.getY());
        }

        final ParametricUnivariateFunction function = new PolynomialFunction.Parametric();
        // Start fit from initial guesses that are far from the optimal
        // values.
        // final SimpleCurveFitter fitter =
        // SimpleCurveFitter.create(function,
        // new double[] { -1e20, 3e15, -5e25 });
        final SimpleCurveFitter fitter = SimpleCurveFitter.create(function,
                new double[] { -2e20, 1e15, -1e25 });
        // 2e2 ist 2*10^2 = 2*100
        final double[] best = fitter.fit(obs.toList());
        // System.out.println("Parameters: " + best.length);
        // funktion ausgeben
        result = new PolynomialFunction(best);
    } catch (Exception e) {
        // e.printStackTrace();
        System.out.println("PolynomialFunction: " + e);
    }
    return result;
}

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