From f64734e8729cab0f5b20baf45bc873282f547bdb Mon Sep 17 00:00:00 2001 From: Phil Steitz Date: Sun, 20 Jun 2004 16:53:17 +0000 Subject: [PATCH] Changed implementation to use TreeMap directly, eliminating [collections] depenency. git-svn-id: https://svn.apache.org/repos/asf/jakarta/commons/proper/math/trunk@141328 13f79535-47bb-0310-9956-ffa450edef68 --- .../apache/commons/math/stat/Frequency.java | 168 +++++++++++------- 1 file changed, 106 insertions(+), 62 deletions(-) diff --git a/src/java/org/apache/commons/math/stat/Frequency.java b/src/java/org/apache/commons/math/stat/Frequency.java index 614dc4e0f..eaf58013f 100644 --- a/src/java/org/apache/commons/math/stat/Frequency.java +++ b/src/java/org/apache/commons/math/stat/Frequency.java @@ -16,23 +16,26 @@ package org.apache.commons.math.stat; import java.io.Serializable; +import java.text.NumberFormat; import java.util.Iterator; import java.util.Comparator; -import java.text.NumberFormat; - -import org.apache.commons.collections.ComparatorUtils; -import org.apache.commons.collections.SortedBag; -import org.apache.commons.collections.bag.TreeBag; +import java.util.TreeMap; /** * Maintains a frequency distribution. *

- * Accepts int, long, char or Object values. New values added must be comparable to - * those that have been added, otherwise the add method will throw an IllegalArgumentException. - * The values are ordered using the default (natural order), unless a Comparator - * is supplied in the constructor. + * Accepts int, long, char or Object values. New values added must be + * comparable to those that have been added, otherwise the add method will + * throw an IllegalArgumentException. + *

+ * Integer values (int, long, Integer, Long) are not distinguished by type -- + * i.e. addValue(new Long(2)), addValue(2), addValue(2l) all have + * the same effect (similarly for arguments to getCount, etc.). + *

+ * The values are ordered using the default (natural order), unless a + * Comparatoris supplied in the constructor. * - * @version $Revision: 1.22 $ $Date: 2004/06/02 00:24:52 $ + * @version $Revision: 1.23 $ $Date: 2004/06/20 16:53:17 $ */ public class Frequency implements Serializable { @@ -40,33 +43,35 @@ public class Frequency implements Serializable { static final long serialVersionUID = -3845586908418844111L; /** underlying collection */ - private SortedBag freqTable = null; + private TreeMap freqTable = null; /** * Default constructor. */ public Frequency() { - freqTable = new TreeBag(); + freqTable = new TreeMap(); } /** * Constructor allowing values Comparator to be specified. + * * @param comparator Comparator used to order values */ public Frequency(Comparator comparator) { - freqTable = new TreeBag(comparator); + freqTable = new TreeMap(comparator); } /** * Return a string representation of this frequency * distribution. + * * @return a string representation. */ public String toString() { NumberFormat nf = NumberFormat.getPercentInstance(); StringBuffer outBuffer = new StringBuffer(); outBuffer.append("Value \t Freq. \t Pct. \t Cum Pct. \n"); - Iterator iter = freqTable.uniqueSet().iterator(); + Iterator iter = freqTable.keySet().iterator(); while (iter.hasNext()) { Object value = iter.next(); outBuffer.append(value); @@ -82,21 +87,28 @@ public class Frequency implements Serializable { } /** - * Adds 1 to the frequency count for v + * Adds 1 to the frequency count for v. + * * @param v the value to add. * @throws IllegalArgumentException if v is not comparable. */ public void addValue(Object v) { try { - freqTable.add(v); + Long count = (Long) freqTable.get(v); + if (count == null) { + freqTable.put(v, new Long(1)); + } else { + freqTable.put(v, new Long(count.longValue() + 1)); + } } catch (ClassCastException ex) { - //TreeBag will throw ClassCastException if v is not comparable + //TreeMap will throw ClassCastException if v is not comparable throw new IllegalArgumentException("Value not comparable to existing values."); } } /** - * Adds 1 to the frequency count for v + * Adds 1 to the frequency count for v. + * * @param v the value to add. */ public void addValue(int v) { @@ -105,6 +117,7 @@ public class Frequency implements Serializable { /** * Adds 1 to the frequency count for v. + * * @param v the value to add. */ public void addValue(long v) { @@ -113,6 +126,7 @@ public class Frequency implements Serializable { /** * Adds 1 to the frequency count for v. + * * @param v the value to add. */ public void addValue(char v) { @@ -126,31 +140,42 @@ public class Frequency implements Serializable { /** * Returns an Iterator over the set of values that have been added. + * * @return values Iterator */ public Iterator valuesIterator() { - return freqTable.uniqueSet().iterator(); + return freqTable.keySet().iterator(); } //------------------------------------------------------------------------- /** - * Returns the sum of all frequencies + * Returns the sum of all frequencies. + * * @return the total frequency count. */ public long getSumFreq() { - return freqTable.size(); + long result = 0; + Iterator iterator = freqTable.values().iterator(); + while (iterator.hasNext()) { + result += ((Long) iterator.next()).longValue(); + } + return result; } /** - * Returns the number of values = v + * Returns the number of values = v. + * * @param v the value to lookup. * @return the frequency of v. */ public long getCount(Object v) { long result = 0; try { - result = freqTable.getCount(v); + Long count = (Long) freqTable.get(v); + if (count != null) { + result = count.longValue(); + } } catch (ClassCastException ex) { // ignore and return 0 -- ClassCastException will be thrown if value is not comparable } @@ -158,48 +183,33 @@ public class Frequency implements Serializable { } /** - * Returns the number of values = v + * Returns the number of values = v. + * * @param v the value to lookup. * @return the frequency of v. */ public long getCount(int v) { - long result = 0; - try { - result = freqTable.getCount(new Long(v)); - } catch (ClassCastException ex) { - // ignore and return 0 -- ClassCastException will be thrown if value is not comparable - } - return result; + return getCount(new Long(v)); } /** - * Returns the number of values = v + * Returns the number of values = v. + * * @param v the value to lookup. * @return the frequency of v. */ public long getCount(long v) { - long result = 0; - try { - result = freqTable.getCount(new Long(v)); - } catch (ClassCastException ex) { - // ignore and return 0 -- ClassCastException will be thrown if value is not comparable - } - return result; + return getCount(new Long(v)); } /** - * Returns the number of values = v + * Returns the number of values = v. + * * @param v the value to lookup. * @return the frequency of v. */ public long getCount(char v) { - long result = 0; - try { - result = freqTable.getCount(new Character(v)); - } catch (ClassCastException ex) { - // ignore and return 0 -- ClassCastException will be thrown if value is not comparable - } - return result; + return getCount(new Character(v)); } //------------------------------------------------------------- @@ -207,7 +217,8 @@ public class Frequency implements Serializable { /** * Returns the percentage of values that are equal to v * (as a proportion between 0 and 1). - * @param v the value to lookup. + * + * @param v the value to lookup * @return the proportion of values equal to v */ public double getPct(Object v) { @@ -217,7 +228,8 @@ public class Frequency implements Serializable { /** * Returns the percentage of values that are equal to v * (as a proportion between 0 and 1). - * @param v the value to lookup. + * + * @param v the value to lookup * @return the proportion of values equal to v */ public double getPct(int v) { @@ -227,7 +239,8 @@ public class Frequency implements Serializable { /** * Returns the percentage of values that are equal to v * (as a proportion between 0 and 1). - * @param v the value to lookup. + * + * @param v the value to lookup * @return the proportion of values equal to v */ public double getPct(long v) { @@ -237,7 +250,8 @@ public class Frequency implements Serializable { /** * Returns the percentage of values that are equal to v * (as a proportion between 0 and 1). - * @param v the value to lookup. + * + * @param v the value to lookup * @return the proportion of values equal to v */ public double getPct(char v) { @@ -257,20 +271,27 @@ public class Frequency implements Serializable { public long getCumFreq(Object v) { Comparator c = freqTable.comparator(); if (c == null) { - c = ComparatorUtils.NATURAL_COMPARATOR; + c = new NaturalComparator(); } long result = 0; + try { - result = freqTable.getCount(v); + Long value = (Long) freqTable.get(v); + if (value != null) { + result = value.longValue(); + } } catch (ClassCastException ex) { return result; // v is not comparable } - if (c.compare(v, freqTable.first()) < 0) { + + if (c.compare(v, freqTable.firstKey()) < 0) { return 0; // v is comparable, but less than first value } - if (c.compare(v, freqTable.last()) >= 0) { + + if (c.compare(v, freqTable.lastKey()) >= 0) { return getSumFreq(); // v is comparable, but greater than the last value } + Iterator values = valuesIterator(); while (values.hasNext()) { Object nextValue = values.next(); @@ -288,7 +309,7 @@ public class Frequency implements Serializable { *

* Returns 0 if v is not comparable to the values set. * - * @param v the value to lookup. + * @param v the value to lookup * @return the proportion of values equal to v */ public long getCumFreq(int v) { @@ -300,7 +321,7 @@ public class Frequency implements Serializable { *

* Returns 0 if v is not comparable to the values set. * - * @param v the value to lookup. + * @param v the value to lookup * @return the proportion of values equal to v */ public long getCumFreq(long v) { @@ -312,7 +333,7 @@ public class Frequency implements Serializable { *

* Returns 0 if v is not comparable to the values set. * - * @param v the value to lookup. + * @param v the value to lookup * @return the proportion of values equal to v */ public long getCumFreq(char v) { @@ -327,7 +348,7 @@ public class Frequency implements Serializable { *

* Returns 0 if v is not comparable to the values set. * - * @param v the value to lookup. + * @param v the value to lookup * @return the proportion of values less than or equal to v */ public double getCumPct(Object v) { @@ -340,7 +361,7 @@ public class Frequency implements Serializable { *

* Returns 0 if v is not comparable to the values set. * - * @param v the value to lookup. + * @param v the value to lookup * @return the proportion of values less than or equal to v */ public double getCumPct(int v) { @@ -353,7 +374,7 @@ public class Frequency implements Serializable { *

* Returns 0 if v is not comparable to the values set. * - * @param v the value to lookup. + * @param v the value to lookup * @return the proportion of values less than or equal to v */ public double getCumPct(long v) { @@ -366,10 +387,33 @@ public class Frequency implements Serializable { *

* Returns 0 if v is not comparable to the values set. * - * @param v the value to lookup. + * @param v the value to lookup * @return the proportion of values less than or equal to v */ public double getCumPct(char v) { return getCumPct(new Character(v)); } + + /** + * A Comparator that compares comparable objects using the + * natural order. Copied from Commons Collections ComparableComparator. + */ + private class NaturalComparator implements Comparator { + /** + * Compare the two {@link Comparable Comparable} arguments. + * This method is equivalent to: + * 

(({@link Comparable Comparable})o1).{@link Comparable#compareTo compareTo}(o2)
+ * + * @param o1 the first object + * @param o2 the second object + * @return result of comparison + * @throws NullPointerException when o1 is null, + * or when ((Comparable)o1).compareTo(o2) does + * @throws ClassCastException when o1 is not a {@link Comparable Comparable}, + * or when ((Comparable)o1).compareTo(o2) does + */ + public int compare(Object o1, Object o2) { + return ((Comparable)o1).compareTo(o2); + } + } }