Mercurial > dive4elements > river
view flys-artifacts/src/main/java/de/intevation/flys/artifacts/math/WKmsOperation.java @ 999:b0218f21c664
Wire datacage with backend of artifact database.
flys-artifacts/trunk@2438 c6561f87-3c4e-4783-a992-168aeb5c3f6f
author | Sascha L. Teichmann <sascha.teichmann@intevation.de> |
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date | Mon, 01 Aug 2011 14:58:15 +0000 |
parents | 0cb1a70b8b92 |
children | 302461d5d071 |
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package de.intevation.flys.artifacts.math; import de.intevation.flys.artifacts.model.WKms; import de.intevation.flys.artifacts.model.WKmsImpl; import java.util.Arrays; public abstract class WKmsOperation { public static final double EPSILON = 1e-6; public static final class KmW implements Comparable<KmW> { protected double km; protected double w; public KmW(double km, double w) { this.km = km; this.w = w; } public int compareTo(KmW other) { return km < other.km ? -1 : km > other.km ? +1 : 0; } public boolean kmEquals(KmW other) { return Math.abs(km - other.km) < EPSILON; } public double subtract(KmW other) { return w - other.w; } } // class KmW public static final WKmsOperation SUBTRACTION = new WKmsOperation() { @Override public WKms operate(WKms a, WKms b) { return subtract(a, b); } }; protected WKmsOperation() { } public abstract WKms operate(WKms a, WKms b); public static WKms subtract(WKms minuend, WKms subtrahend) { int M = minuend .size(); int S = subtrahend.size(); // Don't subtract empty sets if (M < 1 || S < 1) { return new WKmsImpl(); } KmW [] ms = new KmW[M]; KmW [] ss = new KmW[S]; for (int i = 0; i < M; ++i) { ms[i] = new KmW(minuend.getKm(i), minuend.getW(i)); } for (int i = 0; i < S; ++i) { ss[i] = new KmW(subtrahend.getKm(i), subtrahend.getW(i)); } Arrays.sort(ms); Arrays.sort(ss); // no overlap -> empty result set if (ms[0].km > ss[S-1].km || ss[0].km > ms[M-1].km) { return new WKmsImpl(); } WKmsImpl result = new WKmsImpl(); int mi = 0; int si = 0; OUT: while (mi < M && si < S) { KmW m = ms[mi]; KmW s = ss[si]; if (m.km + EPSILON < s.km) { // minuend is before subtrahend while (ms[mi].km + EPSILON < s.km) { if (++mi >= M) { break OUT; } } if (ms[mi].km + EPSILON > s.km) { double mw = Linear.linear( s.km, ms[mi-1].km, ms[mi].km, ms[mi-1].w, ms[mi].w); result.add(s.km, mw - s.w); ++si; } else { // s.km == ms[mi].km result.add(s.km, ms[mi].subtract(s)); ++mi; ++si; } } else if (m.km > s.km + EPSILON) { // subtrahend is before minuend while (m.km > ss[si].km + EPSILON) { if (++si >= S) { break OUT; } } if (ss[si].km + EPSILON > m.km) { double sw = Linear.linear( m.km, ss[si-1].km, ss[si].km, ss[si-1].w, ss[si].w); result.add(m.km, m.w - sw); } else { // ss[si].km == m.km result.add(m.km, m.subtract(ss[si])); ++mi; ++si; } } else { // m.km == s.km result.add(s.km, m.subtract(s)); ++mi; ++si; } } return result; } } // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf-8 :