Example usage for org.apache.commons.math.analysis PolynomialSplineFunction getKnots

Introduction

In this page you can find the example usage for org.apache.commons.math.analysis PolynomialSplineFunction getKnots.

Prototype

public double[] getKnots() 

Source Link

Document

Returns an array copy of the knot points.

Usage

From source file:org.xenmaster.scheduler.analytics.Modeler.java

public static void main(String[] args) {
    try {/* w  w w  .  j  a v  a2s.  c  o m*/
        ArrayList<Double> vals;
        try (BufferedReader br = new BufferedReader(new FileReader("data.csv"))) {
            vals = new ArrayList<>();
            String line = br.readLine();
            while (line != null) {
                String[] split = StringUtils.split(line, ',');
                vals.add(Double.parseDouble(split[0]));
                line = br.readLine();
            }
        }

        double[] idx = new double[1440];
        for (int i = 0; i < idx.length; i++) {
            idx[i] = i;
        }
        double y[] = new double[1440];
        for (int i = 0; i < idx.length; i++) {
            y[i] = vals.get(i).doubleValue();
        }
        SplineInterpolator si = new SplineInterpolator();
        PolynomialSplineFunction psf = (PolynomialSplineFunction) si.interpolate(idx, y);

        for (int i = 0; i < 3; i++) {
            psf = psf.polynomialSplineDerivative();
        }

        try (BufferedWriter bw = new BufferedWriter(new FileWriter("derp.csv", false))) {
            for (double i = psf.getKnots()[0]; i < psf.getKnots()[psf.getKnots().length - 1]; i++) {
                bw.append("" + psf.value(i) + "\n");
            }
        } catch (ArgumentOutsideDomainException | IOException ex) {

        }

    } catch (IOException ex) {
        Logger.getLogger(Modeler.class.getName()).log(Level.SEVERE, null, ex);
    }
}

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