--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/artifacts/src/main/java/org/dive4elements/river/artifacts/model/sq/Outlier.java	Thu Apr 25 15:23:37 2013 +0200
@@ -0,0 +1,93 @@
+package org.dive4elements.river.artifacts.model.sq;
+
+import org.dive4elements.river.artifacts.math.GrubbsOutlier;
+import org.dive4elements.river.artifacts.math.StdDevOutlier;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.commons.math.MathException;
+
+import org.apache.log4j.Logger;
+
+public class Outlier
+{
+    private static Logger log = Logger.getLogger(Outlier.class);
+
+    private static final String GRUBBS = "outlier.method.grubbs";
+
+    //private static final String STD_DEV = "std-dev";
+
+    public interface Callback {
+
+        void initialize(List<SQ> sqs) throws MathException;
+
+        double eval(SQ sq);
+
+        void iterationFinished(
+            double   stdDev,
+            SQ       outlier,
+            List<SQ> remaining);
+
+    } // interface Callback
+
+    public static void detectOutliers(
+        Callback callback,
+        List<SQ> sqs,
+        double   stdDevFactor,
+        String   method
+    )
+    throws MathException
+    {
+        boolean debug = log.isDebugEnabled();
+
+        if (method == null) {
+            method = "std-dev";
+        }
+
+        if (debug) {
+            log.debug("stdDevFactor: " + stdDevFactor);
+            log.debug("method: " + method);
+        }
+
+        List<SQ> data = new ArrayList<SQ>(sqs);
+
+        double [] stdDev = new double[1];
+
+        boolean useGrubbs = method.equals(GRUBBS);
+
+        if (useGrubbs) {
+            stdDevFactor = Math.max(0d, Math.min(stdDevFactor/100d, 1d));
+        }
+
+        List<Double> values = new ArrayList<Double>(data.size());
+
+        while (data.size() > 2) {
+
+            callback.initialize(data);
+
+            for (SQ sq: data) {
+                values.add(callback.eval(sq));
+            }
+
+            Integer ndx = useGrubbs
+                ? GrubbsOutlier.findOutlier(values, stdDevFactor, stdDev)
+                : StdDevOutlier.findOutlier(values, stdDevFactor, stdDev);
+
+            if (ndx == null) {
+                callback.iterationFinished(stdDev[0], null, data);
+                break;
+            }
+
+            SQ outlier = data.remove(ndx.intValue());
+            if (debug) {
+                log.debug("stdDev: " + stdDev[0]);
+                log.debug("removed " + ndx +
+                    "; S: " + outlier.getS() + " Q: " + outlier.getQ());
+            }
+            callback.iterationFinished(stdDev[0], outlier, data);
+            values.clear();
+        }
+    }
+}
+// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :