Mercurial > dive4elements > gnv-client
view gnv-artifacts/src/main/java/de/intevation/gnv/math/LinearFunction.java @ 592:3c939c95c477
Removed accidental checkin of Test-Shapefiles
gnv-artifacts/trunk@647 c6561f87-3c4e-4783-a992-168aeb5c3f6f
author | Tim Englich <tim.englich@intevation.de> |
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date | Fri, 29 Jan 2010 13:28:28 +0000 |
parents | d9d933e06875 |
children | 9a828e5a2390 |
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package de.intevation.gnv.math; import org.apache.commons.math.optimization.fitting.ParametricRealFunction; import org.apache.commons.math.FunctionEvaluationException; import org.apache.commons.math.analysis.UnivariateRealFunction; /** * @author Sascha L. Teichmann (sascha.teichmann@intevation.de) */ public class LinearFunction implements ParametricRealFunction { public static final LinearFunction INSTANCE = new LinearFunction(); public static class Univariate implements UnivariateRealFunction { protected double m; protected double b; public Univariate() { } public Univariate(double x1, double y1, double x2, double y2) { if (y1 == y2) { m = 0d; b = (x1 + x2)*0.5d; } else { m = (x1 - x2)/(y1 - y2); b = y1 - m*x1; } } public double value(double x) { return m*x + b; } } // class Univariate public LinearFunction() { } public double value(double x, double [] parameters) throws FunctionEvaluationException { return x*parameters[0] + parameters[1]; } public double [] gradient(double x, double [] parameters) throws FunctionEvaluationException { return new double [] { x, 1f }; } } // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :