Mercurial > dive4elements > river
comparison flys-artifacts/src/main/java/org/dive4elements/river/artifacts/math/fitting/Quad.java @ 5831:bd047b71ab37
Repaired internal references
| author | Sascha L. Teichmann <teichmann@intevation.de> |
|---|---|
| date | Thu, 25 Apr 2013 12:06:39 +0200 |
| parents | flys-artifacts/src/main/java/de/intevation/flys/artifacts/math/fitting/Quad.java@de67497de5a0 |
| children |
comparison
equal
deleted
inserted
replaced
| 5830:160f53ee0870 | 5831:bd047b71ab37 |
|---|---|
| 1 package org.dive4elements.river.artifacts.math.fitting; | |
| 2 | |
| 3 public class Quad | |
| 4 extends Function | |
| 5 { | |
| 6 public static final Derivative DERIVATIVE = | |
| 7 new Derivative("W'(Q) = 2*n*Q+m") { | |
| 8 | |
| 9 @Override | |
| 10 public org.dive4elements.river.artifacts.math.Function | |
| 11 instantiate(double [] parameters) | |
| 12 { | |
| 13 final double n2 = 2d*parameters[0]; | |
| 14 final double m = parameters[1]; | |
| 15 | |
| 16 return new org.dive4elements.river.artifacts.math.Function() { | |
| 17 @Override | |
| 18 public double value(double Q) { | |
| 19 return n2*Q+m; | |
| 20 } | |
| 21 }; | |
| 22 } | |
| 23 }; | |
| 24 | |
| 25 public static final Function INSTANCE = new Quad(); | |
| 26 | |
| 27 public Quad() { | |
| 28 super( | |
| 29 "quad", | |
| 30 "W(Q) = n*Q^2 + m*Q + b", | |
| 31 new String [] { "n", "m", "b" }); | |
| 32 } | |
| 33 | |
| 34 @Override | |
| 35 public double value(double x, double [] parameters) { | |
| 36 // n*Q^2 + m*Q + b <=> Q*(n*Q + m) + b | |
| 37 return x*(parameters[0]*x + parameters[1]) + parameters[2]; | |
| 38 } | |
| 39 | |
| 40 @Override | |
| 41 public double [] gradient(double x, double [] parameters) { | |
| 42 return new double [] { x*x, x, 1d }; | |
| 43 } | |
| 44 | |
| 45 @Override | |
| 46 public Derivative getDerivative() { | |
| 47 return DERIVATIVE; | |
| 48 } | |
| 49 | |
| 50 @Override | |
| 51 public Function getInverse() { | |
| 52 return InvQuad.INSTANCE; | |
| 53 } | |
| 54 } | |
| 55 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 : |