Mercurial > dive4elements > river
view flys-artifacts/src/main/java/de/intevation/flys/artifacts/math/fitting/InvExp.java @ 4656:442fbb290fa8
Introduce river mapfile generation (WARNING: Changes in config xml files required!).
On startup the RiverMapfileGeneratorStarter is called by the server app.
The starter invokes a call to RiverMapfileGenerator.generate() which
reads all available rivers from the database and generates
layers for each river (in theory...uncompleted) in a
river.map file.
The old MapfileGenerator which generates layers that have
artifact dependencies is now in ArtifactMapfileGenerator.
author | Christian Lins <christian.lins@intevation.de> |
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date | Tue, 11 Dec 2012 15:24:24 +0100 |
parents | 585c0b49e696 |
children |
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package de.intevation.flys.artifacts.math.fitting; public class InvExp extends Function { public static final Derivative DERIVATIVE = new Derivative("W'(Q) = 1/(log(a)*(Q-b))") { @Override public de.intevation.flys.artifacts.math.Function instantiate(double [] parameters) { final double a = parameters[1]; final double b = parameters[2]; final double loga = Math.log(a); return new de.intevation.flys.artifacts.math.Function() { @Override public double value(double Q) { return 1d/(loga*(Q-a)); } }; } }; public static final Function INSTANCE = new InvExp(); public InvExp() { super( "inv-exp", "Q(W) = log((W-b)/m)/log(a)", new String [] { "m", "a", "b" }); } @Override public double value(double W, double [] parameters) { double m = parameters[0]; double a = parameters[1]; double b = parameters[2]; return Math.log((W-b)/m)/Math.log(a); } @Override public double [] gradient(double Q, double [] parameters) { double m = parameters[0]; double a = parameters[1]; double b = parameters[2]; double loga = Math.log(a); return new double [] { -1d/(loga*m), -Math.log((Q-b)/m)/(a*loga*loga), -1d/(loga*(Q-b)) }; } @Override public Derivative getDerivative() { return DERIVATIVE; } @Override public Function getInverse() { return Exp.INSTANCE; } } // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :