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

Introduction

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

Prototype

public PolynomialSplineFunction polynomialSplineDerivative() 

Source Link

Document

Returns the derivative of the polynomial spline function as a PolynomialSplineFunction

Usage

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

public static void main(String[] args) {
    try {//w w  w  . j av a  2  s .  c om
        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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