Mercurial > dive4elements > river
comparison flys-artifacts/src/main/java/de/intevation/flys/artifacts/math/fitting/LogLinear.java @ 2569:0dd58ab7e118
Added functions to be used for fitting in the "Fixierungsanalyse" and "Extremwertermittlung".
flys-artifacts/trunk@4095 c6561f87-3c4e-4783-a992-168aeb5c3f6f
author | Sascha L. Teichmann <sascha.teichmann@intevation.de> |
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date | Mon, 27 Feb 2012 14:16:30 +0000 |
parents | |
children | 4dda67a893da |
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2568:53e8bffbe06c | 2569:0dd58ab7e118 |
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1 package de.intevation.flys.artifacts.math.fitting; | |
2 | |
3 public class LogLinear | |
4 extends Function | |
5 { | |
6 public LogLinear() { | |
7 super( | |
8 "log-linear", | |
9 "W(Q) = a*ln(m*Q + b)", | |
10 new String [] { "a", "m", "b" }); | |
11 } | |
12 | |
13 @Override | |
14 public double value(double x, double [] parameters) { | |
15 return parameters[0]*Math.log(parameters[1]*x + parameters[2]); | |
16 } | |
17 | |
18 @Override | |
19 public double [] gradient(double x, double [] parameters) { | |
20 double l = parameters[1]*x + parameters[2]; | |
21 return new double [] { | |
22 Math.log(l), | |
23 parameters[0]*x/l, | |
24 parameters[0]/l | |
25 }; | |
26 } | |
27 } | |
28 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 : |