Mercurial > dive4elements > river
view flys-artifacts/src/main/java/de/intevation/flys/artifacts/math/BackJumpCorrector.java @ 4655:cd44d28d0fbc
Move the access to artifact data to the Access object
Use BedHeightAccess class to receive the data from the artifact. This abstracts
the data access from the actual artifact.
author | Björn Ricks <bjoern.ricks@intevation.de> |
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date | Tue, 11 Dec 2012 09:44:04 +0100 |
parents | 5642a83420f2 |
children |
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package de.intevation.flys.artifacts.math; import java.util.ArrayList; import java.util.List; import java.io.Serializable; import org.apache.commons.math.analysis.interpolation.SplineInterpolator; import org.apache.commons.math.analysis.polynomials.PolynomialSplineFunction; import org.apache.commons.math.ArgumentOutsideDomainException; import org.apache.commons.math.exception.MathIllegalArgumentException; import org.apache.log4j.Logger; import de.intevation.flys.artifacts.model.Calculation; import de.intevation.flys.utils.DoubleUtil; public class BackJumpCorrector implements Serializable { private static Logger log = Logger.getLogger(BackJumpCorrector.class); protected ArrayList<Double> backjumps; protected double [] corrected; public BackJumpCorrector() { backjumps = new ArrayList<Double>(); } public boolean hasBackJumps() { return !backjumps.isEmpty(); } public List<Double> getBackJumps() { return backjumps; } public double [] getCorrected() { return corrected; } public boolean doCorrection( double [] km, double [] ws, Calculation errors ) { boolean wsUp = DoubleUtil.isIncreasing(ws); if (wsUp) { km = DoubleUtil.swapClone(km); ws = DoubleUtil.swapClone(ws); } boolean kmUp = DoubleUtil.isIncreasing(km); if (!kmUp) { km = DoubleUtil.sumDiffs(km); } if (log.isDebugEnabled()) { log.debug("BackJumpCorrector.doCorrection ------- enter"); log.debug(" km increasing: " + DoubleUtil.isIncreasing(km)); log.debug(" ws increasing: " + DoubleUtil.isIncreasing(ws)); log.debug("BackJumpCorrector.doCorrection ------- leave"); } boolean hasBackJumps = doCorrectionClean(km, ws, errors); if (hasBackJumps && wsUp) { // mirror back DoubleUtil.swap(corrected); } return hasBackJumps; } protected boolean doCorrectionClean( double [] km, double [] ws, Calculation errors ) { int N = km.length; if (N != ws.length) { throw new IllegalArgumentException("km.length != ws.length"); } if (N < 2) { return false; } SplineInterpolator interpolator = null; for (int i = 1; i < N; ++i) { if (ws[i] <= ws[i-1]) { // no back jump continue; } backjumps.add(km[i]); if (corrected == null) { // lazy cloning ws = corrected = (double [])ws.clone(); } double above = aboveWaterKM(km, ws, i); if (Double.isNaN(above)) { // run over start km // fill all previous for (int j = 0; j < i; ++j) { ws[j] = ws[i]; } continue; } double distance = Math.abs(km[i] - above); double quarterDistance = 0.25*distance; double start = above - quarterDistance; double startHeight = DoubleUtil.interpolateSorted(km, ws, start); if (Double.isNaN(startHeight)) { // run over start km startHeight = ws[0]; } double between = above + quarterDistance; double aboveHeight = ws[i] + 0.25*(startHeight - ws[i]); double [] x = { start, above, between }; double [] y = { startHeight, aboveHeight, ws[i] }; if (log.isDebugEnabled()) { for (int j = 0; j < x.length; ++j) { log.debug(" " + x[j] + " -> " + y[j]); } } if (interpolator == null) { interpolator = new SplineInterpolator(); } PolynomialSplineFunction spline; try { spline = interpolator.interpolate(x, y); } catch (MathIllegalArgumentException miae) { errors.addProblem("spline.creation.failed"); log.error(miae); continue; } try { if (log.isDebugEnabled()) { log.debug("spline points:"); for (int j = 0; j < x.length; ++j) { log.debug(x[j] + " " + y[j] + " " + spline.value(x[j])); } } int j = i-1; for (; j >= 0 && km[j] >= between; --j) { ws[j] = ws[i]; } for (; j >= 0 && ws[j] < startHeight; --j) { ws[j] = spline.value(km[j]); } } catch (ArgumentOutsideDomainException aode) { errors.addProblem("spline.interpolation.failed"); log.error("spline interpolation failed", aode); } } // for all km return !backjumps.isEmpty(); } protected static double aboveWaterKM( double [] km, double [] ws, int wIndex ) { double w = ws[wIndex]; while (--wIndex >= 0) { // still under water if (ws[wIndex] < w) continue; if (ws[wIndex] > w) { // f(ws[wIndex]) = km[wIndex] // f(ws[wIndex+1]) = km[wIndex+1] return Linear.linear( w, ws[wIndex], ws[wIndex+1], km[wIndex], km[wIndex+1]); } else { return km[wIndex]; } } return Double.NaN; } } // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :