--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/flys-artifacts/src/main/java/org/dive4elements/river/artifacts/math/fitting/Function.java	Thu Apr 25 12:06:39 2013 +0200
@@ -0,0 +1,100 @@
+package org.dive4elements.river.artifacts.math.fitting;
+
+import org.apache.commons.math.FunctionEvaluationException;
+
+import org.apache.commons.math.optimization.fitting.ParametricRealFunction;
+
+import org.dive4elements.river.utils.DoubleUtil;
+
+public abstract class Function
+implements            ParametricRealFunction
+{
+    protected String    name;
+    protected String    description;
+    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 org.dive4elements.river.artifacts.math.Function
+            instantiate(double [] parameters);
+
+    } // interface Derivative
+
+    public Function() {
+    }
+
+    public Function(
+        String    name,
+        String    description,
+        String [] parameterNames
+    ) {
+        this(name,
+            description,
+            parameterNames,
+            DoubleUtil.fill(parameterNames.length, 1d));
+    }
+
+    public Function(
+        String    name,
+        String    description,
+        String [] parameterNames,
+        double [] initialGuess
+    ) {
+        this.name           = name;
+        this.description    = description;
+        this.parameterNames = parameterNames;
+        this.initialGuess   = initialGuess;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public String getDescription() {
+        return description;
+    }
+
+    public String [] getParameterNames() {
+        return parameterNames;
+    }
+
+    public double [] getInitialGuess() {
+        return initialGuess;
+    }
+
+    public org.dive4elements.river.artifacts.math.Function instantiate(
+        final double [] parameters
+    ) {
+        return new org.dive4elements.river.artifacts.math.Function() {
+
+            @Override
+            public double value(double x) {
+                try {
+                    return Function.this.value(x, parameters);
+                }
+                catch (FunctionEvaluationException fee) {
+                    return Double.NaN;
+                }
+            }
+        };
+    }
+
+    public abstract Derivative getDerivative();
+
+    public abstract Function getInverse();
+}
+// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :