From 6b269625c948a944f4883e975421db6fc9de9f15 Mon Sep 17 00:00:00 2001
From: darksnake <darksnake@LUNA>
Date: Thu, 30 Jun 2016 13:09:30 +0300
Subject: [PATCH] [no commit message]

---
 .../src/main/java/inr/numass/utils/EventChainGenerator.java  | 1 +
 .../src/main/java/inr/numass/utils/NMEventGenerator.java     | 4 ++--
 .../src/main/java/inr/numass/utils/PileUpSimulator.java      | 5 +++--
 3 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/numass-main/src/main/java/inr/numass/utils/EventChainGenerator.java b/numass-main/src/main/java/inr/numass/utils/EventChainGenerator.java
index ab42e046..cf22d621 100644
--- a/numass-main/src/main/java/inr/numass/utils/EventChainGenerator.java
+++ b/numass-main/src/main/java/inr/numass/utils/EventChainGenerator.java
@@ -21,6 +21,7 @@ import static java.lang.Math.max;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
+import static java.lang.Math.max;
 
 /**
  * Utility class for pile-up simulation
diff --git a/numass-main/src/main/java/inr/numass/utils/NMEventGenerator.java b/numass-main/src/main/java/inr/numass/utils/NMEventGenerator.java
index f97bf756..014919bc 100644
--- a/numass-main/src/main/java/inr/numass/utils/NMEventGenerator.java
+++ b/numass-main/src/main/java/inr/numass/utils/NMEventGenerator.java
@@ -122,10 +122,10 @@ public class NMEventGenerator {
             chanel = 1600;
         }
 
-        return new NMEvent(chanel, prev == null ? 0 : prev.getTime() + nextExp(1 / cr));
+        return new NMEvent(chanel, prev == null ? 0 : prev.getTime() + nextExpDecay(1 / cr));
     }
 
-    public double nextExp(double mean) {
+    public double nextExpDecay(double mean) {
         double rand = this.nextUniform();
         return -mean * Math.log(1 - rand);
     }
diff --git a/numass-main/src/main/java/inr/numass/utils/PileUpSimulator.java b/numass-main/src/main/java/inr/numass/utils/PileUpSimulator.java
index 4d42d5c9..7ed78e6f 100644
--- a/numass-main/src/main/java/inr/numass/utils/PileUpSimulator.java
+++ b/numass-main/src/main/java/inr/numass/utils/PileUpSimulator.java
@@ -118,7 +118,7 @@ public class PileUpSimulator {
             //flag that shows that previous event was pileup
             //not counting double pileups
             if (current != null) {
-                double delay = (next.getTime() - current.getTime()) / us;
+                double delay = (next.getTime() - current.getTime()) / us; //time between events in microseconds
                 if (nextEventRegistered(delay)) {
                     //just register new event
                     registred.add(next.clone());
@@ -131,9 +131,10 @@ public class PileUpSimulator {
                     registred.remove(registred.size() - 1);
                     registred.add(newEvent.clone());
                     pileup.add(newEvent.clone());
-                    pileupFlag = true;
+                    pileupFlag = true; // up the flag to avoid secondary pileup
                 } else {
                     // second event not registered
+                    pileupFlag = false;
                 }
             } else {
                 //register first event