Mercurial > dive4elements > river
comparison flys-artifacts/src/main/java/de/intevation/flys/artifacts/math/fitting/Exp.java @ 3009:4dda67a893da
FixA: Added the derivatives of all fitting functions.
flys-artifacts/trunk@4565 c6561f87-3c4e-4783-a992-168aeb5c3f6f
| author | Sascha L. Teichmann <sascha.teichmann@intevation.de> |
|---|---|
| date | Thu, 31 May 2012 16:32:03 +0000 |
| parents | 0dd58ab7e118 |
| children | 585c0b49e696 |
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inserted
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| 3008:9e0500d64524 | 3009:4dda67a893da |
|---|---|
| 1 package de.intevation.flys.artifacts.math.fitting; | 1 package de.intevation.flys.artifacts.math.fitting; |
| 2 | 2 |
| 3 public class Exp | 3 public class Exp |
| 4 extends Function | 4 extends Function |
| 5 { | 5 { |
| 6 public static final Derivative DERIVATIVE = | |
| 7 new Derivative("W'(Q) = a^Q*log(a)*m") { | |
| 8 | |
| 9 @Override | |
| 10 public de.intevation.flys.artifacts.math.Function | |
| 11 instantiate(double [] parameters) | |
| 12 { | |
| 13 final double m = parameters[0]; | |
| 14 final double a = parameters[1]; | |
| 15 | |
| 16 return new de.intevation.flys.artifacts.math.Function() { | |
| 17 @Override | |
| 18 public double value(double Q) { | |
| 19 return Math.pow(a, Q)*Math.log(a)*m; | |
| 20 } | |
| 21 }; | |
| 22 } | |
| 23 }; | |
| 24 | |
| 6 public Exp() { | 25 public Exp() { |
| 7 super( | 26 super( |
| 8 "exp", | 27 "exp", |
| 9 "W(Q) = m * a^Q + b", | 28 "W(Q) = m * a^Q + b", |
| 10 new String [] { "m", "a", "b" }); | 29 new String [] { "m", "a", "b" }); |
| 21 Math.pow(parameters[1], x), | 40 Math.pow(parameters[1], x), |
| 22 Math.pow(parameters[1], x-1d)*x, | 41 Math.pow(parameters[1], x-1d)*x, |
| 23 1d | 42 1d |
| 24 }; | 43 }; |
| 25 } | 44 } |
| 45 | |
| 46 @Override | |
| 47 public Derivative getDerivative() { | |
| 48 return DERIVATIVE; | |
| 49 } | |
| 26 } | 50 } |
| 27 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 : | 51 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 : |