Mercurial > dive4elements > gnv-client
view gnv-artifacts/src/main/java/de/intevation/gnv/math/XYColumn.java @ 592:3c939c95c477
Removed accidental checkin of Test-Shapefiles
gnv-artifacts/trunk@647 c6561f87-3c4e-4783-a992-168aeb5c3f6f
author | Tim Englich <tim.englich@intevation.de> |
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date | Fri, 29 Jan 2010 13:28:28 +0000 |
parents | bc5901bb4525 |
children | b1f5f2a8840f |
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package de.intevation.gnv.math; import java.util.ArrayList; import java.util.List; import java.util.Collections; import org.apache.commons.math.analysis.interpolation.SplineInterpolator; import org.apache.commons.math.analysis.interpolation.UnivariateRealInterpolator; import org.apache.commons.math.analysis.UnivariateRealFunction; import org.apache.commons.math.MathException; import org.apache.commons.math.FunctionEvaluationException; import org.apache.log4j.Logger; /** * @author Ingo Weinzierl <ingo.weinzierl@intevation.de> * @author Sascha L. Teichmann <sascha.teichmann@intevation.de> */ public class XYColumn extends Point2d implements UnivariateRealFunction { private static Logger log = Logger.getLogger(XYColumn.class); protected List<HeightValue> values; protected transient UnivariateRealFunction curve; public XYColumn() { values = new ArrayList<HeightValue>(); } public XYColumn(double x, double y, int i, int j) { super(x, y, i, j); values = new ArrayList<HeightValue>(); } public void add(HeightValue value) { values.add(value); } public List<HeightValue> getValues() { return values; } public double value(double depth) { try { if (curve != null) { HeightValue h = values.get(0); // extrapolate beyond boundaries by repeating if (depth > h.z) return h.v; h = values.get(values.size()-1); if (depth < h.z) return h.v; return curve.value(depth); } } catch (FunctionEvaluationException fee) { log.error("evaluation failed", fee); } return Double.NaN; } public boolean prepare(XYDepth xyDepth) { if (curve == null) { int N = values.size(); if (N == 0) { log.error("no points for interpolation"); return false; } if (N == 1) { // only one value -> constant function curve = new ConstantFunction(values.get(0).v); } else { // more than on value double depth = xyDepth.depth(this); Collections.sort(values, HeightValue.INV_Z_COMPARATOR); // if there is no value at 0 repeat first value HeightValue first = values.get(0); if (first.z < 0d) { values.add(0, new HeightValue(0d, first.v, first.k-1)); ++N; } // if there is no value at depth repeat last value HeightValue last = values.get(N-1); if (last.z > depth) { values.add(new HeightValue(depth, last.v, last.k+1)); ++N; } if (N < 3) { // interpolate linear first = values.get(0); last = values.get(N-1); curve = new LinearFunction.Univariate( first.z, first.v, last.z, last.v); } else { // higher degree interpolation double [] z = new double[N]; double [] v = new double[N]; for (int i = 0; i < N; ++i) { HeightValue h = values.get(N-1-i); z[i] = h.z; v[i] = h.v; } try { curve = getInterpolator().interpolate(z, v); } catch (MathException me) { log.error("interpolation failed", me); return false; } } } } return true; } protected UnivariateRealInterpolator getInterpolator() { return new SplineInterpolator(); } } // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8: