Mercurial > dive4elements > river
view artifacts/src/main/java/org/dive4elements/river/artifacts/math/MovingAverage.java @ 8755:30b1ddadf275
(issue1801) Unify reference gauge finding code
The basic way as described in the method comment of the
determineRefGauge method is now used in the WINFOArtifact,
MainValuesService and RiverUtils.getGauge method.
RiverUtils.getGauge previously just returned the first
gauge found. While this is now a behavior change I believe
that it is always more correct then the undeterministic
behavior of the previous implmenentation.
author | Andre Heinecke <andre.heinecke@intevation.de> |
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date | Wed, 24 Jun 2015 14:07:26 +0200 |
parents | 34c15927f9d9 |
children | 96c41d4f4aba |
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/* Copyright (C) 2011, 2012, 2013 by Bundesanstalt für Gewässerkunde * Software engineering by Intevation GmbH * * This file is Free Software under the GNU AGPL (>=v3) * and comes with ABSOLUTELY NO WARRANTY! Check out the * documentation coming with Dive4Elements River for details. */ package org.dive4elements.river.artifacts.math; import java.util.Map; import java.util.SortedMap; import java.util.TreeMap; public class MovingAverage { public static double[][] simple(double[][] values, double radius) { TreeMap<Double, Double> map = toMap(values); int N = map.size(); double [] xs = new double[N]; double [] ys = new double[N]; int ndx = 0; for (double x: map.keySet()) { SortedMap<Double, Double> range = map.subMap(x-radius, true, x+radius, true); double avg = 0d; for (double v: range.values()) { avg += v; } avg /= range.size(); xs[ndx] = x; ys[ndx] = avg; ndx++; } return new double [][] { xs, ys }; } /** Build moving average over values. Weight them. */ public static double[][] weighted( double[][] values, double radius ) { TreeMap<Double, Double> map = toMap(values); int N = map.size(); double [] xs = new double[N]; double [] ys = new double[N]; int ndx = 0; double _1radius = 1d/radius; for (double x: map.keySet()) { double avg = 0d; double weights = 0d; for (Map.Entry<Double, Double> e: map.subMap(x-radius, false, x+radius, false).entrySet() ) { double weight = 1d - Math.abs(x - e.getKey())*_1radius; avg += weight*e.getValue(); weights += weight; } avg /= weights; xs[ndx] = x; ys[ndx] = avg; ndx++; } return new double [][] { xs, ys }; } /** From [x1,x2][y1,y2] makes {x1:y1,x2:y2}. Sorted by x! */ private static TreeMap<Double, Double> toMap(double[][] values) { TreeMap<Double, Double> map = new TreeMap<Double, Double>(); double [] xs = values[0]; double [] ys = values[1]; for (int i = 0; i < xs.length; i++) { map.put(xs[i], ys[i]); } return map; } } // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :