Mercurial > dive4elements > river
comparison flys-artifacts/src/main/java/de/intevation/flys/artifacts/model/extreme/Curve.java @ 3786:4adc35aa655c
merged flys-artifacts/2.9.1
| author | Thomas Arendsen Hein <thomas@intevation.de> |
|---|---|
| date | Fri, 28 Sep 2012 12:14:47 +0200 |
| parents | 467efea19d15 |
| children | 5cc9453456a7 |
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| 3719:e82acd5c86f7 | 3786:4adc35aa655c |
|---|---|
| 1 package de.intevation.flys.artifacts.model.extreme; | |
| 2 | |
| 3 import de.intevation.flys.artifacts.math.Function; | |
| 4 import de.intevation.flys.artifacts.math.NaNFunction; | |
| 5 import de.intevation.flys.artifacts.math.UnivariateRealFunctionFunction; | |
| 6 | |
| 7 import de.intevation.flys.artifacts.math.fitting.FunctionFactory; | |
| 8 | |
| 9 import java.io.Serializable; | |
| 10 | |
| 11 import java.lang.ref.SoftReference; | |
| 12 | |
| 13 import org.apache.commons.math.analysis.interpolation.SplineInterpolator; | |
| 14 | |
| 15 import org.apache.commons.math.exception.MathIllegalArgumentException; | |
| 16 | |
| 17 import org.apache.log4j.Logger; | |
| 18 | |
| 19 public class Curve | |
| 20 implements Serializable, Function | |
| 21 { | |
| 22 private static Logger log = Logger.getLogger(Curve.class); | |
| 23 | |
| 24 protected double [] qs; | |
| 25 protected double [] ws; | |
| 26 protected String function; | |
| 27 protected double [] coeffs; | |
| 28 | |
| 29 // The spline is pretty heavy weight so cache it with a soft ref only. | |
| 30 protected transient SoftReference<Function> spline; | |
| 31 protected transient Function extrapolation; | |
| 32 | |
| 33 public Curve() { | |
| 34 } | |
| 35 | |
| 36 public Curve( | |
| 37 double [] qs, | |
| 38 double [] ws, | |
| 39 String function, | |
| 40 double [] coeffs | |
| 41 ) { | |
| 42 this.qs = qs; | |
| 43 this.ws = ws; | |
| 44 this.function = function; | |
| 45 this.coeffs = coeffs; | |
| 46 } | |
| 47 | |
| 48 public double [] getQs() { | |
| 49 return qs; | |
| 50 } | |
| 51 | |
| 52 public double [] getWs() { | |
| 53 return ws; | |
| 54 } | |
| 55 | |
| 56 public String getFunction() { | |
| 57 return function; | |
| 58 } | |
| 59 | |
| 60 public double [] getCoeffs() { | |
| 61 return coeffs; | |
| 62 } | |
| 63 | |
| 64 @Override | |
| 65 public double value(double x) { | |
| 66 if (x < qs[0]) return Double.NaN; | |
| 67 return (x <= qs[qs.length-1] | |
| 68 ? getSpline() | |
| 69 : getExtrapolation()).value(x); | |
| 70 } | |
| 71 | |
| 72 protected synchronized Function getExtrapolation() { | |
| 73 if (extrapolation == null) { | |
| 74 de.intevation.flys.artifacts.math.fitting.Function | |
| 75 f = FunctionFactory.getInstance().getFunction(function); | |
| 76 | |
| 77 extrapolation = f != null | |
| 78 ? f.instantiate(coeffs) | |
| 79 : NaNFunction.INSTANCE; | |
| 80 } | |
| 81 return extrapolation; | |
| 82 } | |
| 83 | |
| 84 protected synchronized Function getSpline() { | |
| 85 Function sp; | |
| 86 if (spline != null) { | |
| 87 if ((sp = spline.get()) != null) { | |
| 88 return sp; | |
| 89 } | |
| 90 } | |
| 91 spline = new SoftReference<Function>(sp = createSpline()); | |
| 92 return sp; | |
| 93 } | |
| 94 | |
| 95 protected Function createSpline() { | |
| 96 SplineInterpolator interpolator = new SplineInterpolator(); | |
| 97 try { | |
| 98 return new UnivariateRealFunctionFunction( | |
| 99 interpolator.interpolate(qs, ws)); | |
| 100 } | |
| 101 catch (MathIllegalArgumentException miae) { | |
| 102 log.debug("creation on spline failed", miae); | |
| 103 return NaNFunction.INSTANCE; | |
| 104 } | |
| 105 } | |
| 106 } | |
| 107 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf-8 : |