From 04d470232ee8de204fad5d0339c32d646be3a5c5 Mon Sep 17 00:00:00 2001
From: Sebastian Bazley <sebb@apache.org>
Date: Fri, 17 Apr 2009 13:07:26 +0000
Subject: [PATCH] Make HashMap final as it is only set in the ctors Document
 behaviour of getCount(Object v) if v is not comparable Save value of
 getSumFreq() from DIV/0 check so we don't calculate it twice

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/math/trunk@765978 13f79535-47bb-0310-9956-ffa450edef68
---
 .../org/apache/commons/math/stat/Frequency.java     | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/src/java/org/apache/commons/math/stat/Frequency.java b/src/java/org/apache/commons/math/stat/Frequency.java
index ac909c1fe..a5b8d7b60 100644
--- a/src/java/org/apache/commons/math/stat/Frequency.java
+++ b/src/java/org/apache/commons/math/stat/Frequency.java
@@ -49,7 +49,7 @@ public class Frequency implements Serializable {
     private static final long serialVersionUID = -3845586908418844111L;
 
     /** underlying collection */
-    private TreeMap freqTable = null;
+    private final TreeMap freqTable;
 
     /**
      * Default constructor.
@@ -193,6 +193,7 @@ public class Frequency implements Serializable {
 
     /**
      * Returns the number of values = v.
+     * Returns 0 if the value is not comparable.
      * 
      * @param v the value to lookup.
      * @return the frequency of v.
@@ -255,10 +256,11 @@ public class Frequency implements Serializable {
      * @return the proportion of values equal to v
      */
     public double getPct(Object v) {
-        if (getSumFreq() == 0) {
+        final long sumFreq = getSumFreq();
+        if (sumFreq == 0) {
             return Double.NaN;
         }
-        return (double) getCount(v) / (double) getSumFreq();        
+        return (double) getCount(v) / (double) sumFreq;        
     }
     
     /**
@@ -396,10 +398,11 @@ public class Frequency implements Serializable {
      * @return the proportion of values less than or equal to v
      */
     public double getCumPct(Object v) {
-        if (getSumFreq() == 0) {
+        final long sumFreq = getSumFreq();
+        if (sumFreq == 0) {
             return Double.NaN;
         }
-        return (double) getCumFreq(v) / (double) getSumFreq();        
+        return (double) getCumFreq(v) / (double) sumFreq;        
     }
     
     /**