Mercurial > dive4elements > river
view flys-artifacts/src/main/java/de/intevation/flys/artifacts/math/fitting/Log.java @ 3133:6f6a8e5fb7a4
Theme updates for sector average wq curves/points
flys-artifacts/trunk@4740 c6561f87-3c4e-4783-a992-168aeb5c3f6f
author | Christian Lins <christian.lins@intevation.de> |
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date | Thu, 21 Jun 2012 12:26:08 +0000 |
parents | 4dda67a893da |
children | 6b13d7e7b403 |
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package de.intevation.flys.artifacts.math.fitting; public class Log extends Function { public static final Derivative DERIVATIVE = new Derivative("W'(Q) = m/(Q+b)") { @Override public de.intevation.flys.artifacts.math.Function instantiate(double [] parameters) { final double m = parameters[0]; final double b = parameters[1]; return new de.intevation.flys.artifacts.math.Function() { @Override public double value(double Q) { return m/(Q+b); } }; } }; public Log() { super("log", "W(Q) = m*ln(Q + b)", new String [] { "m", "b" }); } @Override public double value(double x, double [] parameters) { return parameters[0]*Math.log(x + parameters[1]); } @Override public double [] gradient(double x, double [] parameters) { return new double [] { Math.log(x + parameters[1]), parameters[0]/(x + parameters[0]) }; } @Override public Derivative getDerivative() { return DERIVATIVE; } } // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :