90 lines
2.4 KiB
Java
90 lines
2.4 KiB
Java
package presenter.algorithms.naiv;
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import model.Line;
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import presenter.algorithms.Algorithm;
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import presenter.util.FastElementSelector;
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import java.util.ArrayList;
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import java.util.LinkedList;
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/**
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* Implementierung verschiedener Algorithmen zur Berechnung von Ausgleichsgeraden.
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*
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* @Author: Armin Wolf
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* @Email: a_wolf28@uni-muenster.de
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* @Date: 15.09.2017.
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*/
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public class NaivTheilSenEstimator implements Algorithm {
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private LinkedList<Line> lines;
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private double slope;
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private double yInterception;
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/**
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* Konstruktor
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* @param lines Liste der Geraden
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*/
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public NaivTheilSenEstimator(LinkedList<Line> lines) {
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this.lines = lines;
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this.slope = 0d;
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this.yInterception = 0d;
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}
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@Override
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public void run() {
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System.out.println("=== S T A R T - naiv T S ===");
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long start;
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long end;
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start = System.currentTimeMillis();
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ArrayList<Double> slopesList = new ArrayList<>();
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int cnt = 0;
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for (int i = 0; i < lines.size(); i++) {
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double x = lines.get(i).getM();
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double y = lines.get(i).getB();
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for (int j = i + 1; j < lines.size(); j++) {
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if (x != lines.get(j).getM()) { // x must be different, otherwise slope becomes infinite
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Double slope = (lines.get(j).getB() - y) / (lines.get(j).getM() - x);
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slopesList.add(slope);
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++cnt;
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}
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}
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}
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ArrayList<Double> list1 = new ArrayList<>();
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ArrayList<Double> list2 = new ArrayList<>();
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for (int i = 0; i < lines.size(); i++) {
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list1.add(lines.get(i).getM());
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list2.add(lines.get(i).getB());
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}
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double median1 = FastElementSelector.randomizedSelect(list1, list1.size() / 2);
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double median2 = FastElementSelector.randomizedSelect(list2, list2.size() / 2);
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slope = FastElementSelector.randomizedSelect(slopesList, slopesList.size() / 2);
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yInterception = median2 - slope * median1;
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end = System.currentTimeMillis();
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System.out.println("Zeit: "+ ((end-start)/1000));
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}
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@Override
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public void pepareResult() {
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}
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/**
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* @return Steigung
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*/
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public double getM() {
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return slope * -1;
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}
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/**
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* @return y-Achsenabschnitt
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*/
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public double getB() {
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return yInterception * -1;
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}
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}
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