# HG changeset patch
# User Sascha L. Teichmann <sascha.teichmann@intevation.de>
# Date 1338481923 0
# Node ID 4dda67a893da23397dc9e1d5c69828be24352e38
# Parent  9e0500d645245835e4724529274defbed0e655fc
FixA: Added the derivatives of all fitting functions.

flys-artifacts/trunk@4565 c6561f87-3c4e-4783-a992-168aeb5c3f6f

diff -r 9e0500d64524 -r 4dda67a893da flys-artifacts/ChangeLog
--- a/flys-artifacts/ChangeLog	Wed May 30 17:59:19 2012 +0000
+++ b/flys-artifacts/ChangeLog	Thu May 31 16:32:03 2012 +0000
@@ -1,3 +1,17 @@
+2012-05-31	Sascha L. Teichmann	<sascha.teichmann@intevation.de>
+
+	* src/main/java/de/intevation/flys/artifacts/math/fitting/Function.java:
+	  Added inner class Derivative representing the first derivative of the
+	  function. Can be instantiated with a given set of parameters.
+
+	* src/main/java/de/intevation/flys/artifacts/math/fitting/Log.java,
+	  src/main/java/de/intevation/flys/artifacts/math/fitting/Pow.java,
+	  src/main/java/de/intevation/flys/artifacts/math/fitting/Linear.java,
+	  src/main/java/de/intevation/flys/artifacts/math/fitting/Quad.java,
+	  src/main/java/de/intevation/flys/artifacts/math/fitting/Exp.java,
+	  src/main/java/de/intevation/flys/artifacts/math/fitting/LogLinear.java:
+	  Added the derivatives of all fitting functions.
+
 2012-05-30	Sascha L. Teichmann	<sascha.teichmann@intevation.de>
 
 	* src/main/java/de/intevation/flys/artifacts/model/fixings/FixCalculation.java:
diff -r 9e0500d64524 -r 4dda67a893da flys-artifacts/src/main/java/de/intevation/flys/artifacts/math/fitting/Exp.java
--- a/flys-artifacts/src/main/java/de/intevation/flys/artifacts/math/fitting/Exp.java	Wed May 30 17:59:19 2012 +0000
+++ b/flys-artifacts/src/main/java/de/intevation/flys/artifacts/math/fitting/Exp.java	Thu May 31 16:32:03 2012 +0000
@@ -3,6 +3,25 @@
 public class Exp
 extends      Function
 {
+    public static final Derivative DERIVATIVE =
+        new Derivative("W'(Q) = a^Q*log(a)*m") {
+
+        @Override
+        public de.intevation.flys.artifacts.math.Function
+            instantiate(double [] parameters)
+        {
+            final double m = parameters[0];
+            final double a = parameters[1];
+
+            return new de.intevation.flys.artifacts.math.Function() {
+                @Override
+                public double value(double Q) {
+                    return Math.pow(a, Q)*Math.log(a)*m;
+                }
+            };
+        }
+    };
+
     public Exp() {
         super(
             "exp",
@@ -23,5 +42,10 @@
             1d
         };
     }
+
+    @Override
+    public Derivative getDerivative() {
+        return DERIVATIVE;
+    }
 }
 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :
diff -r 9e0500d64524 -r 4dda67a893da flys-artifacts/src/main/java/de/intevation/flys/artifacts/math/fitting/Function.java
--- a/flys-artifacts/src/main/java/de/intevation/flys/artifacts/math/fitting/Function.java	Wed May 30 17:59:19 2012 +0000
+++ b/flys-artifacts/src/main/java/de/intevation/flys/artifacts/math/fitting/Function.java	Thu May 31 16:32:03 2012 +0000
@@ -14,6 +14,26 @@
     protected String [] parameterNames;
     protected double [] initialGuess;
 
+    public static abstract class Derivative {
+
+        protected String description;
+
+        public Derivative() {
+        }
+
+        public Derivative(String description) {
+            this.description = description;
+        }
+
+        public String getDescription() {
+            return description;
+        }
+
+        public abstract de.intevation.flys.artifacts.math.Function
+            instantiate(double [] parameters);
+
+    } // interface Derivative
+
     public Function() {
     }
 
@@ -72,5 +92,7 @@
             }
         };
     }
+
+    public abstract Derivative getDerivative();
 }
 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :
diff -r 9e0500d64524 -r 4dda67a893da flys-artifacts/src/main/java/de/intevation/flys/artifacts/math/fitting/Linear.java
--- a/flys-artifacts/src/main/java/de/intevation/flys/artifacts/math/fitting/Linear.java	Wed May 30 17:59:19 2012 +0000
+++ b/flys-artifacts/src/main/java/de/intevation/flys/artifacts/math/fitting/Linear.java	Thu May 31 16:32:03 2012 +0000
@@ -3,6 +3,24 @@
 public class Linear
 extends      Function
 {
+    public static final Derivative DERIVATIVE =
+        new Derivative("W'(Q) = m") {
+
+        @Override
+        public de.intevation.flys.artifacts.math.Function
+            instantiate(double [] parameters)
+        {
+            final double m = parameters[0];
+
+            return new de.intevation.flys.artifacts.math.Function() {
+                @Override
+                public double value(double Q) {
+                    return m;
+                }
+            };
+        }
+    };
+
     public Linear() {
         super("linear", "W(Q) = m*Q + b", new String [] { "m", "b" });
     }
@@ -16,5 +34,10 @@
     public double [] gradient(double x, double [] parameters) {
         return new double [] { x, 1d };
     }
+
+    @Override
+    public Derivative getDerivative() {
+        return DERIVATIVE;
+    }
 }
 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :
diff -r 9e0500d64524 -r 4dda67a893da flys-artifacts/src/main/java/de/intevation/flys/artifacts/math/fitting/Log.java
--- a/flys-artifacts/src/main/java/de/intevation/flys/artifacts/math/fitting/Log.java	Wed May 30 17:59:19 2012 +0000
+++ b/flys-artifacts/src/main/java/de/intevation/flys/artifacts/math/fitting/Log.java	Thu May 31 16:32:03 2012 +0000
@@ -3,6 +3,25 @@
 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 Log() {
         super("log",  "W(Q) = m*ln(Q + b)", new String [] { "m", "b" });
     }
@@ -19,5 +38,10 @@
             parameters[0]/(x + parameters[0])
         };
     }
+
+    @Override
+    public Derivative getDerivative() {
+        return DERIVATIVE;
+    }
 }
 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :
diff -r 9e0500d64524 -r 4dda67a893da flys-artifacts/src/main/java/de/intevation/flys/artifacts/math/fitting/LogLinear.java
--- a/flys-artifacts/src/main/java/de/intevation/flys/artifacts/math/fitting/LogLinear.java	Wed May 30 17:59:19 2012 +0000
+++ b/flys-artifacts/src/main/java/de/intevation/flys/artifacts/math/fitting/LogLinear.java	Thu May 31 16:32:03 2012 +0000
@@ -3,6 +3,26 @@
 public class LogLinear
 extends      Function
 {
+    public static final Derivative DERIVATIVE =
+        new Derivative("W'(Q) = a*m/(m*Q + b)") {
+
+        @Override
+        public de.intevation.flys.artifacts.math.Function
+            instantiate(double [] parameters)
+        {
+            final double a = parameters[0];
+            final double m = parameters[1];
+            final double b = parameters[2];
+
+            return new de.intevation.flys.artifacts.math.Function() {
+                @Override
+                public double value(double Q) {
+                    return a*m/(m*Q + b);
+                }
+            };
+        }
+    };
+
     public LogLinear() {
         super(
             "log-linear",
@@ -24,5 +44,10 @@
             parameters[0]/l
         };
     }
+
+    @Override
+    public Derivative getDerivative() {
+        return DERIVATIVE;
+    }
 }
 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :
diff -r 9e0500d64524 -r 4dda67a893da flys-artifacts/src/main/java/de/intevation/flys/artifacts/math/fitting/Pow.java
--- a/flys-artifacts/src/main/java/de/intevation/flys/artifacts/math/fitting/Pow.java	Wed May 30 17:59:19 2012 +0000
+++ b/flys-artifacts/src/main/java/de/intevation/flys/artifacts/math/fitting/Pow.java	Thu May 31 16:32:03 2012 +0000
@@ -3,6 +3,25 @@
 public class Pow
 extends      Function
 {
+    public static final Derivative DERIVATIVE =
+        new Derivative("W'(Q) = a*c*Q^(c-1)") {
+
+        @Override
+        public de.intevation.flys.artifacts.math.Function
+            instantiate(double [] parameters)
+        {
+            final double a = parameters[0];
+            final double c = parameters[1];
+
+            return new de.intevation.flys.artifacts.math.Function() {
+                @Override
+                public double value(double Q) {
+                    return a*c*Math.pow(Q, c-1);
+                }
+            };
+        }
+    };
+
     public Pow() {
         super(
             "pow",
@@ -26,5 +45,10 @@
             1d
         };
     }
+
+    @Override
+    public Derivative getDerivative() {
+        return DERIVATIVE;
+    }
 }
 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :
diff -r 9e0500d64524 -r 4dda67a893da flys-artifacts/src/main/java/de/intevation/flys/artifacts/math/fitting/Quad.java
--- a/flys-artifacts/src/main/java/de/intevation/flys/artifacts/math/fitting/Quad.java	Wed May 30 17:59:19 2012 +0000
+++ b/flys-artifacts/src/main/java/de/intevation/flys/artifacts/math/fitting/Quad.java	Thu May 31 16:32:03 2012 +0000
@@ -3,6 +3,25 @@
 public class Quad
 extends      Function
 {
+    public static final Derivative DERIVATIVE =
+        new Derivative("W'(Q) = 2*n*Q+m") {
+
+        @Override
+        public de.intevation.flys.artifacts.math.Function
+            instantiate(double [] parameters)
+        {
+            final double n = parameters[0];
+            final double m = parameters[1];
+
+            return new de.intevation.flys.artifacts.math.Function() {
+                @Override
+                public double value(double Q) {
+                    return 2*n*Q+m;
+                }
+            };
+        }
+    };
+
     public Quad() {
         super(
             "quad",
@@ -20,5 +39,10 @@
     public double [] gradient(double x, double [] parameters) {
         return new double [] { x*x, x, 1d };
     }
+
+    @Override
+    public Derivative getDerivative() {
+        return DERIVATIVE;
+    }
 }
 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :