Example usage for org.jfree.data.statistics Regression getPowerRegression

Introduction

In this page you can find the example usage for org.jfree.data.statistics Regression getPowerRegression.

Prototype

public static double[] getPowerRegression(XYDataset data, int series) 

Source Link

Document

Returns the parameters 'a' and 'b' for an equation y = ax^b, fitted to the data using a power regression equation.

Usage

From source file:org.operamasks.faces.render.graph.ChartRenderer.java

private XYSeries createCurveSeries(UICurve curve, XYDataset data, int index) {
    if (data.getItemCount(index) < 2) {
        throw new IllegalArgumentException("Not enough data");
    }/*from w  w w  .j  a  v a 2  s.  c  om*/

    Key key = new Key(index, curve.getLegend());

    if (curve instanceof UIAverageLine) {
        double period = ((UIAverageLine) curve).getPeriod();
        double skip = ((UIAverageLine) curve).getSkip();
        if (data instanceof TimeSeriesCollection) {
            TimeSeries ts = ((TimeSeriesCollection) data).getSeries(index);
            return MovingAverage.createMovingAverage(ts, key, (int) period, (int) skip);
        } else {
            return MovingAverage.createMovingAverage(data, index, key, period, skip);
        }
    } else if (curve instanceof UIRegressionLine) {
        RegressionType type = ((UIRegressionLine) curve).getType();
        int samples = ((UIRegressionLine) curve).getSamples();
        if (type == null || type == RegressionType.Linear) {
            double[] p = Regression.getOLSRegression(data, index);
            Function2D f = new LineFunction2D(p[0], p[1]);
            return createFunctionSeries(data, index, key, f, samples);
        } else if (type == RegressionType.Power) {
            double[] p = Regression.getPowerRegression(data, index);
            Function2D f = new PowerFunction2D(p[0], p[1]);
            return createFunctionSeries(data, index, key, f, samples);
        } else {
            throw new IllegalArgumentException(type.toString());
        }
    } else if (curve instanceof UISpline) {
        SplineType type = ((UISpline) curve).getType();
        int samples = ((UISpline) curve).getSamples();
        int degree = ((UISpline) curve).getDegree();
        if (type == null || type == SplineType.BSpline) {
            return BSpline.createBSpline(data, index, key, samples, degree);
        } else if (type == SplineType.CubicSpline) {
            return CubicSpline.createCubicSpline(data, index, key, samples);
        }
    }

    return null;
}

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