diff flys-artifacts/src/main/java/de/intevation/flys/artifacts/math/fitting/Exp.java @ 2569:0dd58ab7e118

Added functions to be used for fitting in the "Fixierungsanalyse" and "Extremwertermittlung". flys-artifacts/trunk@4095 c6561f87-3c4e-4783-a992-168aeb5c3f6f
author Sascha L. Teichmann <sascha.teichmann@intevation.de>
date Mon, 27 Feb 2012 14:16:30 +0000
parents
children 4dda67a893da
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/flys-artifacts/src/main/java/de/intevation/flys/artifacts/math/fitting/Exp.java	Mon Feb 27 14:16:30 2012 +0000
@@ -0,0 +1,27 @@
+package de.intevation.flys.artifacts.math.fitting;
+
+public class Exp
+extends      Function
+{
+    public Exp() {
+        super(
+            "exp",
+            "W(Q) = m * a^Q + b",
+            new String [] { "m", "a", "b" });
+    }
+
+    @Override
+    public double value(double x, double [] parameters) {
+        return parameters[0]*Math.pow(parameters[1], x) + parameters[2];
+    }
+
+    @Override
+    public double [] gradient(double x, double [] parameters) {
+        return new double [] {
+            Math.pow(parameters[1], x),
+            Math.pow(parameters[1], x-1d)*x,
+            1d
+        };
+    }
+}
+// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :

http://dive4elements.wald.intevation.org