package de.intevation.flys.artifacts.math.fitting;

public class Log
extends      Function
{
    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])
        };
    }
}
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