Mercurial > dive4elements > river
view flys-artifacts/src/main/java/de/intevation/flys/artifacts/math/fitting/Log.java @ 3230:b888c5eb65b3
Added new *Access objects for bed height calculation and flow velocity calculation; removed methods for specific data access from MINFOArtifact.
flys-artifacts/trunk@4859 c6561f87-3c4e-4783-a992-168aeb5c3f6f
author | Ingo Weinzierl <ingo.weinzierl@intevation.de> |
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date | Tue, 03 Jul 2012 12:13:36 +0000 |
parents | 585c0b49e696 |
children |
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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 static final Function INSTANCE = new Log(); 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) { double m = parameters[0]; double b = parameters[1]; double b_x = b + x; return new double [] { Math.log(b_x), m/b_x }; } @Override public Derivative getDerivative() { return DERIVATIVE; } @Override public Function getInverse() { return InvLog.INSTANCE; } } // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :