diff -N TotalMomentumDriver.java
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ TotalMomentumDriver.java	19 Dec 2012 11:01:03 -0000	1.1
@@ -0,0 +1,39 @@

+package org.lcsim.mcd.analysis;
+
+import hep.aida.ICloud1D;
+import java.util.List;
+import org.lcsim.event.EventHeader;
+import org.lcsim.event.Track;
+import org.lcsim.util.Driver;
+import org.lcsim.util.aida.AIDA;
+
+/**
+ *  Hans Wenzel 
+ *  simple driver to demonstrate access to tracks as created by FastMC
+ * 
+ */
+public class TotalMomentumDriver extends Driver {
+
+    AIDA aida = AIDA.defaultInstance();
+    ICloud1D totMomentumPlot;
+
+    public void startOfData() {
+        totMomentumPlot = aida.cloud1D(" Total Momentum");
+    }
+
+    @Override
+    protected void process(EventHeader event) {
+
+        double ptotal = 0.0;
+        List<Track> tracks = event.getTracks();
+        for (Track track : tracks) {
+            double[] mom = track.getMomentum();
+            ptotal = Math.sqrt(mom[0] * mom[0] + mom[1] * mom[1] + mom[2] * mom[2]);
+        }
+        totMomentumPlot.fill(ptotal); 
+    }
+
+    @Override
+    protected void endOfData() {
+    }
+}