--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/artifacts/src/main/java/org/dive4elements/river/utils/DataUtil.java	Thu Apr 25 15:23:37 2013 +0200
@@ -0,0 +1,34 @@
+package org.dive4elements.river.utils;
+
+import java.util.Random;
+
+import gnu.trove.TDoubleArrayList;
+
+public class DataUtil
+{
+    public static boolean guessWaterIncreasing(TDoubleArrayList data) {
+        return guessWaterIncreasing(data, 0.05f);
+    }
+
+    public static boolean guessWaterIncreasing(TDoubleArrayList data, float factor) {
+        int N = data.size();
+        if (N < 2) return false;
+
+        int samples = (int)(factor*N) + 1;
+
+        int up = 0;
+
+        Random rand = new Random();
+
+        for (int i = 0; i < samples; ++i) {
+            int    pos2 = rand.nextInt(N-1) + 1;
+            int    pos1 = rand.nextInt(pos2);
+            double w1   = data.getQuick(pos1);
+            double w2   = data.getQuick(pos2);
+            if (w2 > w1) ++up;
+        }
+
+        return up > samples/2;
+    }
+}
+// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :