com.opmath.util.datastruct
Class SortedTableIndex

java.lang.Object
  |
  +--java.util.AbstractCollection
        |
        +--java.util.AbstractList
              |
              +--java.util.Vector
                    |
                    +--com.opmath.util.datastruct.ComparableVector
                          |
                          +--com.opmath.util.datastruct.SortedTableIndex

All Implemented Interfaces:

Cloneable, Collection, ComparableList, List, Serializable

public class SortedTableIndex

extends ComparableVector

Provides the means to construct a sorted index for a ComparableTable.

The sorted index function is the familiar one for data tables: a number of columns are nominated, in decreasing order of importance - all rows are sorted for field values in the first column, and subsequent columns are used as 'tie-breakers'.

All field values in the given ComparableTable must implement the java.util.Comparable interface. Since this is the only restriction on the nature of field values, it is up to the programmer to ensure that 'sensible' comparisons are being made.

SortedTableIndex provides its own private class in order to implement an insert sort algorithm. The algorithm is not particularly efficient, but is not disasterous either: where only one column is used for the sort (or no equal values are found) the cost is in the order (n²)/4 comparisons and n inserts. Where further columns are used, and equal values are found, the number of comparisons and inserts grows linearly.

SortedTableIndex implements the ComparableList interface by inheriting from ComparableVector. Access methods for SortedTableIndex are therefore as per ComparableList.

Note that the structures used to implement the sort are discarded by the SortedTableIndex constructor in order to minimize memory requirements.

Copyright: (c) 2002 The Open Math Company Limited

The Terms of Distribution of this software are stipulated in the javadoc Overview for this project.

Since:

J2SE 1.3

Version:

DataStruct v1.0 r1

Author:

Bruno Beloff bruno.beloff@opmath.com

See Also:

Serialized Form

Fields inherited from class java.util.Vector

capacityIncrement, elementCount, elementData

Fields inherited from class java.util.AbstractList

modCount

Constructor Summary

SortedTableIndex(ComparableTable display, ComparableList columnKeys)
Constructs a new sorted index for the given ComparableTable.

Methods inherited from class com.opmath.util.datastruct.ComparableVector

add, set, toString

Methods inherited from class java.util.Vector

add, add, addAll, addAll, addElement, capacity, clear, clone, contains, containsAll, copyInto, elementAt, elements, ensureCapacity, equals, firstElement, get, hashCode, indexOf, indexOf, insertElementAt, isEmpty, lastElement, lastIndexOf, lastIndexOf, remove, remove, removeAll, removeAllElements, removeElement, removeElementAt, removeRange, retainAll, set, setElementAt, setSize, size, subList, toArray, toArray, trimToSize

Methods inherited from class java.util.AbstractList

iterator, listIterator, listIterator

Methods inherited from class java.lang.Object

, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface com.opmath.util.datastruct.ComparableList

clear, elements, get, indexOf, size

Methods inherited from interface java.util.List

iterator, listIterator, listIterator

Constructor Detail

SortedTableIndex

public SortedTableIndex(ComparableTable display,
                        ComparableList columnKeys)
                 throws ComparableTableException

Constructs a new sorted index for the given ComparableTable.

Parameters:

display - the ComparableTable for the sort index.

columnKeys - the ComparableList identifying the sort columns.

Throws:

ComparableTableException - An exception thrown if any column identified in columnKeys is not known to the ComparableTable instance.

Since:

J2SE 1.3