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Posted to commits@mahout.apache.org by gs...@apache.org on 2009/11/23 16:14:38 UTC
svn commit: r883365 [19/47] - in /lucene/mahout/trunk: ./ examples/ matrix/
matrix/src/ matrix/src/main/ matrix/src/main/java/
matrix/src/main/java/org/ matrix/src/main/java/org/apache/
matrix/src/main/java/org/apache/mahout/ matrix/src/main/java/org/a...
Added: lucene/mahout/trunk/matrix/src/main/java/org/apache/mahout/matrix/list/AbstractShortList.java
URL: http://svn.apache.org/viewvc/lucene/mahout/trunk/matrix/src/main/java/org/apache/mahout/matrix/list/AbstractShortList.java?rev=883365&view=auto
==============================================================================
--- lucene/mahout/trunk/matrix/src/main/java/org/apache/mahout/matrix/list/AbstractShortList.java (added)
+++ lucene/mahout/trunk/matrix/src/main/java/org/apache/mahout/matrix/list/AbstractShortList.java Mon Nov 23 15:14:26 2009
@@ -0,0 +1,781 @@
+/*
+Copyright � 1999 CERN - European Organization for Nuclear Research.
+Permission to use, copy, modify, distribute and sell this software and its documentation for any purpose
+is hereby granted without fee, provided that the above copyright notice appear in all copies and
+that both that copyright notice and this permission notice appear in supporting documentation.
+CERN makes no representations about the suitability of this software for any purpose.
+It is provided "as is" without expressed or implied warranty.
+*/
+package org.apache.mahout.colt.list;
+
+import org.apache.mahout.colt.function.ShortComparator;
+import org.apache.mahout.colt.function.ShortProcedure;
+/**
+Abstract base class for resizable lists holding <code>short</code> elements; abstract.
+First see the <a href="package-summary.html">package summary</a> and javadoc <a href="package-tree.html">tree view</a> to get the broad picture.
+*/
+/**
+ * @deprecated until unit tests are in place. Until this time, this class/interface is unsupported.
+ */
+@Deprecated
+public abstract class AbstractShortList extends AbstractList {
+ /**
+ * The size of the list.
+ * This is a READ_ONLY variable for all methods but setSizeRaw(int newSize) !!!
+ * If you violate this principle in subclasses, you should exactly know what you are doing.
+ * @serial
+ */
+ protected int size;
+/**
+ * Makes this class non instantiable, but still let's others inherit from it.
+ */
+protected AbstractShortList() {}
+/**
+ * Appends the specified element to the end of this list.
+ *
+ * @param element element to be appended to this list.
+ */
+public void add(short element) {
+ beforeInsert(size,element);
+}
+/**
+ * Appends the part of the specified list between <code>from</code> (inclusive) and <code>to</code> (inclusive) to the receiver.
+ *
+ * @param other the list to be added to the receiver.
+ * @param from the index of the first element to be appended (inclusive).
+ * @param to the index of the last element to be appended (inclusive).
+ * @exception IndexOutOfBoundsException index is out of range (<tt>other.size()>0 && (from<0 || from>to || to>=other.size())</tt>).
+ */
+public void addAllOfFromTo(AbstractShortList other, int from, int to) {
+ beforeInsertAllOfFromTo(size,other,from,to);
+}
+/**
+ * Inserts the specified element before the specified position into the receiver.
+ * Shifts the element currently at that position (if any) and
+ * any subsequent elements to the right.
+ *
+ * @param index index before which the specified element is to be inserted (must be in [0,size]).
+ * @param element element to be inserted.
+ * @exception IndexOutOfBoundsException index is out of range (<tt>index < 0 || index > size()</tt>).
+ */
+public void beforeInsert(int index, short element) {
+ beforeInsertDummies(index,1);
+ set(index,element);
+}
+/**
+ * Inserts the part of the specified list between <code>otherFrom</code> (inclusive) and <code>otherTo</code> (inclusive) before the specified position into the receiver.
+ * Shifts the element currently at that position (if any) and
+ * any subsequent elements to the right.
+ *
+ * @param index index before which to insert first element from the specified list (must be in [0,size])..
+ * @param other list of which a part is to be inserted into the receiver.
+ * @param from the index of the first element to be inserted (inclusive).
+ * @param to the index of the last element to be inserted (inclusive).
+ * @exception IndexOutOfBoundsException index is out of range (<tt>other.size()>0 && (from<0 || from>to || to>=other.size())</tt>).
+ * @exception IndexOutOfBoundsException index is out of range (<tt>index < 0 || index > size()</tt>).
+ */
+public void beforeInsertAllOfFromTo(int index, AbstractShortList other, int from, int to) {
+ int length=to-from+1;
+ this.beforeInsertDummies(index, length);
+ this.replaceFromToWithFrom(index, index+length-1, other, from);
+}
+/**
+ * Inserts <tt>length</tt> dummy elements before the specified position into the receiver.
+ * Shifts the element currently at that position (if any) and
+ * any subsequent elements to the right.
+ * <b>This method must set the new size to be <tt>size()+length</tt>.
+ *
+ * @param index index before which to insert dummy elements (must be in [0,size])..
+ * @param length number of dummy elements to be inserted.
+ * @throws IndexOutOfBoundsException if <tt>index < 0 || index > size()</tt>.
+ */
+protected void beforeInsertDummies(int index, int length) {
+ if (index > size || index < 0)
+ throw new IndexOutOfBoundsException("Index: "+index+", Size: "+size);
+ if (length > 0) {
+ ensureCapacity(size + length);
+ setSizeRaw(size + length);
+ replaceFromToWithFrom(index+length,size-1,this,index);
+ }
+}
+/**
+ * Searches the receiver for the specified value using
+ * the binary search algorithm. The receiver must <strong>must</strong> be
+ * sorted (as by the sort method) prior to making this call. If
+ * it is not sorted, the results are undefined: in particular, the call
+ * may enter an infinite loop. If the receiver contains multiple elements
+ * equal to the specified object, there is no guarantee which instance
+ * will be found.
+ *
+ * @param key the value to be searched for.
+ * @return index of the search key, if it is contained in the receiver;
+ * otherwise, <tt>(-(<i>insertion point</i>) - 1)</tt>. The <i>insertion
+ * point</i> is defined as the the point at which the value would
+ * be inserted into the receiver: the index of the first
+ * element greater than the key, or <tt>receiver.size()</tt>, if all
+ * elements in the receiver are less than the specified key. Note
+ * that this guarantees that the return value will be >= 0 if
+ * and only if the key is found.
+ * @see java.util.Arrays
+ */
+public int binarySearch(short key) {
+ return this.binarySearchFromTo(key, 0, size-1);
+}
+/**
+ * Searches the receiver for the specified value using
+ * the binary search algorithm. The receiver must <strong>must</strong> be
+ * sorted (as by the sort method) prior to making this call. If
+ * it is not sorted, the results are undefined: in particular, the call
+ * may enter an infinite loop. If the receiver contains multiple elements
+ * equal to the specified object, there is no guarantee which instance
+ * will be found.
+ *
+ * @param key the value to be searched for.
+ * @param from the leftmost search position, inclusive.
+ * @param to the rightmost search position, inclusive.
+ * @return index of the search key, if it is contained in the receiver;
+ * otherwise, <tt>(-(<i>insertion point</i>) - 1)</tt>. The <i>insertion
+ * point</i> is defined as the the point at which the value would
+ * be inserted into the receiver: the index of the first
+ * element greater than the key, or <tt>receiver.size()</tt>, if all
+ * elements in the receiver are less than the specified key. Note
+ * that this guarantees that the return value will be >= 0 if
+ * and only if the key is found.
+ * @see java.util.Arrays
+ */
+public int binarySearchFromTo(short key, int from, int to) {
+ int low=from;
+ int high=to;
+ while (low <= high) {
+ int mid =(low + high)/2;
+ short midVal = get(mid);
+
+ if (midVal < key) low = mid + 1;
+ else if (midVal > key) high = mid - 1;
+ else return mid; // key found
+ }
+ return -(low + 1); // key not found.
+}
+/**
+ * Returns a deep copy of the receiver.
+ *
+ * @return a deep copy of the receiver.
+ */
+public Object clone() {
+ return partFromTo(0,size-1);
+}
+/**
+ * Returns true if the receiver contains the specified element.
+ *
+ * @param element element whose presence in the receiver is to be tested.
+ */
+public boolean contains(short elem) {
+ return indexOfFromTo(elem,0,size-1) >=0;
+}
+/**
+ * Deletes the first element from the receiver that is identical to the specified element.
+ * Does nothing, if no such matching element is contained.
+ *
+ * @param element the element to be deleted.
+ */
+public void delete(short element) {
+ int index = indexOfFromTo(element, 0, size-1);
+ if (index>=0) remove(index);
+}
+/**
+ * Returns the elements currently stored, possibly including invalid elements between size and capacity.
+ *
+ * <b>WARNING:</b> For efficiency reasons and to keep memory usage low, this method may decide <b>not to copy the array</b>.
+ * So if subsequently you modify the returned array directly via the [] operator, be sure you know what you're doing.
+ *
+ * @return the elements currently stored.
+ */
+public short[] elements() {
+ short[] myElements = new short[size];
+ for (int i=size; --i >= 0; ) myElements[i]=getQuick(i);
+ return myElements;
+}
+/**
+ * Sets the receiver's elements to be the specified array.
+ * The size and capacity of the list is the length of the array.
+ * <b>WARNING:</b> For efficiency reasons and to keep memory usage low, this method may decide <b>not to copy the array</b>.
+ * So if subsequently you modify the returned array directly via the [] operator, be sure you know what you're doing.
+ *
+ * @param elements the new elements to be stored.
+ * @return the receiver itself.
+ */
+public AbstractShortList elements(short[] elements) {
+ clear();
+ addAllOfFromTo(new ShortArrayList(elements),0,elements.length-1);
+ return this;
+}
+/**
+ * Ensures that the receiver can hold at least the specified number of elements without needing to allocate new internal memory.
+ * If necessary, allocates new internal memory and increases the capacity of the receiver.
+ *
+ * @param minCapacity the desired minimum capacity.
+ */
+public abstract void ensureCapacity(int minCapacity);
+/**
+ * Compares the specified Object with the receiver.
+ * Returns true if and only if the specified Object is also an ArrayList of the same type, both Lists have the
+ * same size, and all corresponding pairs of elements in the two Lists are identical.
+ * In other words, two Lists are defined to be equal if they contain the
+ * same elements in the same order.
+ *
+ * @param otherObj the Object to be compared for equality with the receiver.
+ * @return true if the specified Object is equal to the receiver.
+ */
+public boolean equals(Object otherObj) { //delta
+ if (! (otherObj instanceof AbstractShortList)) {return false;}
+ if (this==otherObj) return true;
+ if (otherObj==null) return false;
+ AbstractShortList other = (AbstractShortList) otherObj;
+ if (size()!=other.size()) return false;
+
+ for (int i=size(); --i >= 0; ) {
+ if (getQuick(i) != other.getQuick(i)) return false;
+ }
+ return true;
+}
+/**
+ * Sets the specified range of elements in the specified array to the specified value.
+ *
+ * @param from the index of the first element (inclusive) to be filled with the specified value.
+ * @param to the index of the last element (inclusive) to be filled with the specified value.
+ * @param val the value to be stored in the specified elements of the receiver.
+ */
+public void fillFromToWith(int from, int to, short val) {
+ checkRangeFromTo(from,to,this.size);
+ for (int i=from; i<=to;) setQuick(i++,val);
+}
+/**
+ * Applies a procedure to each element of the receiver, if any.
+ * Starts at index 0, moving rightwards.
+ * @param procedure the procedure to be applied. Stops iteration if the procedure returns <tt>false</tt>, otherwise continues.
+ * @return <tt>false</tt> if the procedure stopped before all elements where iterated over, <tt>true</tt> otherwise.
+ */
+public boolean forEach(ShortProcedure procedure) {
+ for (int i=0; i<size;) if (! procedure.apply(get(i++))) return false;
+ return true;
+}
+/**
+ * Returns the element at the specified position in the receiver.
+ *
+ * @param index index of element to return.
+ * @exception IndexOutOfBoundsException index is out of range (index
+ * < 0 || index >= size()).
+ */
+public short get(int index) {
+ if (index >= size || index < 0)
+ throw new IndexOutOfBoundsException("Index: "+index+", Size: "+size);
+ return getQuick(index);
+}
+/**
+ * Returns the element at the specified position in the receiver; <b>WARNING:</b> Does not check preconditions.
+ * Provided with invalid parameters this method may return invalid elements without throwing any exception!
+ * <b>You should only use this method when you are absolutely sure that the index is within bounds.</b>
+ * Precondition (unchecked): <tt>index >= 0 && index < size()</tt>.
+ *
+ * This method is normally only used internally in large loops where bounds are explicitly checked before the loop and need no be rechecked within the loop.
+ * However, when desperately, you can give this method <tt>public</tt> visibility in subclasses.
+ *
+ * @param index index of element to return.
+ */
+protected abstract short getQuick(int index);
+/**
+ * Returns the index of the first occurrence of the specified
+ * element. Returns <code>-1</code> if the receiver does not contain this element.
+ *
+ * @param element the element to be searched for.
+ * @return the index of the first occurrence of the element in the receiver; returns <code>-1</code> if the element is not found.
+ */
+public int indexOf(short element) { //delta
+ return indexOfFromTo(element, 0, size-1);
+}
+/**
+ * Returns the index of the first occurrence of the specified
+ * element. Returns <code>-1</code> if the receiver does not contain this element.
+ * Searches between <code>from</code>, inclusive and <code>to</code>, inclusive.
+ * Tests for identity.
+ *
+ * @param element element to search for.
+ * @param from the leftmost search position, inclusive.
+ * @param to the rightmost search position, inclusive.
+ * @return the index of the first occurrence of the element in the receiver; returns <code>-1</code> if the element is not found.
+ * @exception IndexOutOfBoundsException index is out of range (<tt>size()>0 && (from<0 || from>to || to>=size())</tt>).
+ */
+public int indexOfFromTo(short element, int from, int to) {
+ checkRangeFromTo(from, to, size);
+
+ for (int i = from ; i <= to; i++) {
+ if (element==getQuick(i)) return i; //found
+ }
+ return -1; //not found
+}
+/**
+ * Returns the index of the last occurrence of the specified
+ * element. Returns <code>-1</code> if the receiver does not contain this element.
+ *
+ * @param element the element to be searched for.
+ * @return the index of the last occurrence of the element in the receiver; returns <code>-1</code> if the element is not found.
+ */
+public int lastIndexOf(short element) {
+ return lastIndexOfFromTo(element, 0, size-1);
+}
+/**
+ * Returns the index of the last occurrence of the specified
+ * element. Returns <code>-1</code> if the receiver does not contain this element.
+ * Searches beginning at <code>to</code>, inclusive until <code>from</code>, inclusive.
+ * Tests for identity.
+ *
+ * @param element element to search for.
+ * @param from the leftmost search position, inclusive.
+ * @param to the rightmost search position, inclusive.
+ * @return the index of the last occurrence of the element in the receiver; returns <code>-1</code> if the element is not found.
+ * @exception IndexOutOfBoundsException index is out of range (<tt>size()>0 && (from<0 || from>to || to>=size())</tt>).
+ */
+public int lastIndexOfFromTo(short element, int from, int to) {
+ checkRangeFromTo(from, to, size());
+
+ for (int i = to ; i >= from; i--) {
+ if (element==getQuick(i)) return i; //found
+ }
+ return -1; //not found
+}
+/**
+ * Sorts the specified range of the receiver into ascending order.
+ *
+ * The sorting algorithm is a modified mergesort (in which the merge is
+ * omitted if the highest element in the low sublist is less than the
+ * lowest element in the high sublist). This algorithm offers guaranteed
+ * n*log(n) performance, and can approach linear performance on nearly
+ * sorted lists.
+ *
+ * <p><b>You should never call this method unless you are sure that this particular sorting algorithm is the right one for your data set.</b>
+ * It is generally better to call <tt>sort()</tt> or <tt>sortFromTo(...)</tt> instead, because those methods automatically choose the best sorting algorithm.
+ *
+ * @param from the index of the first element (inclusive) to be sorted.
+ * @param to the index of the last element (inclusive) to be sorted.
+ * @exception IndexOutOfBoundsException index is out of range (<tt>size()>0 && (from<0 || from>to || to>=size())</tt>).
+ */
+public void mergeSortFromTo(int from, int to) {
+ int mySize = size();
+ checkRangeFromTo(from, to, mySize);
+
+ short[] myElements = elements();
+ org.apache.mahout.colt.Sorting.mergeSort(myElements, from, to+1);
+ elements(myElements);
+ setSizeRaw(mySize);
+}
+/**
+ * Sorts the receiver according
+ * to the order induced by the specified comparator. All elements in the
+ * range must be <i>mutually comparable</i> by the specified comparator
+ * (that is, <tt>c.compare(e1, e2)</tt> must not throw a
+ * <tt>ClassCastException</tt> for any elements <tt>e1</tt> and
+ * <tt>e2</tt> in the range).<p>
+ *
+ * This sort is guaranteed to be <i>stable</i>: equal elements will
+ * not be reordered as a result of the sort.<p>
+ *
+ * The sorting algorithm is a modified mergesort (in which the merge is
+ * omitted if the highest element in the low sublist is less than the
+ * lowest element in the high sublist). This algorithm offers guaranteed
+ * n*log(n) performance, and can approach linear performance on nearly
+ * sorted lists.
+ *
+ * @param from the index of the first element (inclusive) to be
+ * sorted.
+ * @param to the index of the last element (inclusive) to be sorted.
+ * @param c the comparator to determine the order of the receiver.
+ * @throws ClassCastException if the array contains elements that are not
+ * <i>mutually comparable</i> using the specified comparator.
+ * @throws IllegalArgumentException if <tt>fromIndex > toIndex</tt>
+ * @throws ArrayIndexOutOfBoundsException if <tt>fromIndex < 0</tt> or
+ * <tt>toIndex > a.length</tt>
+ * @see Comparator
+ * @exception IndexOutOfBoundsException index is out of range (<tt>size()>0 && (from<0 || from>to || to>=size())</tt>).
+ */
+public void mergeSortFromTo(int from, int to, ShortComparator c) {
+ int mySize = size();
+ checkRangeFromTo(from, to, mySize);
+
+ short[] myElements = elements();
+ org.apache.mahout.colt.Sorting.mergeSort(myElements, from, to+1, c);
+ elements(myElements);
+ setSizeRaw(mySize);
+}
+/**
+ * Returns a new list of the part of the receiver between <code>from</code>, inclusive, and <code>to</code>, inclusive.
+ * @param from the index of the first element (inclusive).
+ * @param to the index of the last element (inclusive).
+ * @return a new list
+ * @exception IndexOutOfBoundsException index is out of range (<tt>size()>0 && (from<0 || from>to || to>=size())</tt>).
+ */
+public AbstractShortList partFromTo(int from, int to) {
+ checkRangeFromTo(from, to, size);
+
+ int length = to-from+1;
+ ShortArrayList part = new ShortArrayList(length);
+ part.addAllOfFromTo(this,from,to);
+ return part;
+}
+/**
+ * Sorts the specified range of the receiver into
+ * ascending numerical order. The sorting algorithm is a tuned quicksort,
+ * adapted from Jon L. Bentley and M. Douglas McIlroy's "Engineering a
+ * Sort Function", Software-Practice and Experience, Vol. 23(11)
+ * P. 1249-1265 (November 1993). This algorithm offers n*log(n)
+ * performance on many data sets that cause other quicksorts to degrade to
+ * quadratic performance.
+ *
+ * <p><b>You should never call this method unless you are sure that this particular sorting algorithm is the right one for your data set.</b>
+ * It is generally better to call <tt>sort()</tt> or <tt>sortFromTo(...)</tt> instead, because those methods automatically choose the best sorting algorithm.
+ *
+ * @param from the index of the first element (inclusive) to be sorted.
+ * @param to the index of the last element (inclusive) to be sorted.
+ * @exception IndexOutOfBoundsException index is out of range (<tt>size()>0 && (from<0 || from>to || to>=size())</tt>).
+ */
+public void quickSortFromTo(int from, int to) {
+ int mySize = size();
+ checkRangeFromTo(from, to, mySize);
+
+ short[] myElements = elements();
+ java.util.Arrays.sort(myElements, from, to+1);
+ elements(myElements);
+ setSizeRaw(mySize);
+}
+/**
+ * Sorts the receiver according
+ * to the order induced by the specified comparator. All elements in the
+ * range must be <i>mutually comparable</i> by the specified comparator
+ * (that is, <tt>c.compare(e1, e2)</tt> must not throw a
+ * <tt>ClassCastException</tt> for any elements <tt>e1</tt> and
+ * <tt>e2</tt> in the range).<p>
+ *
+ * The sorting algorithm is a tuned quicksort,
+ * adapted from Jon L. Bentley and M. Douglas McIlroy's "Engineering a
+ * Sort Function", Software-Practice and Experience, Vol. 23(11)
+ * P. 1249-1265 (November 1993). This algorithm offers n*log(n)
+ * performance on many data sets that cause other quicksorts to degrade to
+ * quadratic performance.
+ *
+ * @param from the index of the first element (inclusive) to be
+ * sorted.
+ * @param to the index of the last element (inclusive) to be sorted.
+ * @param c the comparator to determine the order of the receiver.
+ * @throws ClassCastException if the array contains elements that are not
+ * <i>mutually comparable</i> using the specified comparator.
+ * @throws IllegalArgumentException if <tt>fromIndex > toIndex</tt>
+ * @throws ArrayIndexOutOfBoundsException if <tt>fromIndex < 0</tt> or
+ * <tt>toIndex > a.length</tt>
+ * @see Comparator
+ * @exception IndexOutOfBoundsException index is out of range (<tt>size()>0 && (from<0 || from>to || to>=size())</tt>).
+ */
+public void quickSortFromTo(int from, int to, ShortComparator c) {
+ int mySize = size();
+ checkRangeFromTo(from, to, mySize);
+
+ short[] myElements = elements();
+ org.apache.mahout.colt.Sorting.quickSort(myElements, from, to+1,c);
+ elements(myElements);
+ setSizeRaw(mySize);
+}
+/**
+* Removes from the receiver all elements that are contained in the specified list.
+* Tests for identity.
+*
+* @param other the other list.
+* @return <code>true</code> if the receiver changed as a result of the call.
+*/
+public boolean removeAll(AbstractShortList other) {
+ if (other.size()==0) return false; //nothing to do
+ int limit = other.size()-1;
+ int j=0;
+
+ for (int i=0; i<size ; i++) {
+ if (other.indexOfFromTo(getQuick(i), 0, limit) < 0) setQuick(j++,getQuick(i));
+ }
+
+ boolean modified = (j!=size);
+ setSize(j);
+ return modified;
+}
+/**
+ * Removes from the receiver all elements whose index is between
+ * <code>from</code>, inclusive and <code>to</code>, inclusive. Shifts any succeeding
+ * elements to the left (reduces their index).
+ * This call shortens the list by <tt>(to - from + 1)</tt> elements.
+ *
+ * @param from index of first element to be removed.
+ * @param to index of last element to be removed.
+ * @exception IndexOutOfBoundsException index is out of range (<tt>size()>0 && (from<0 || from>to || to>=size())</tt>).
+ */
+public void removeFromTo(int from, int to) {
+ checkRangeFromTo(from, to, size);
+ int numMoved = size - to - 1;
+ if (numMoved > 0) {
+ replaceFromToWithFrom(from, from-1+numMoved, this, to+1);
+ //fillFromToWith(from+numMoved, size-1, 0.0f); //delta
+ }
+ int width = to-from+1;
+ if (width>0) setSizeRaw(size-width);
+}
+/**
+ * Replaces a number of elements in the receiver with the same number of elements of another list.
+ * Replaces elements in the receiver, between <code>from</code> (inclusive) and <code>to</code> (inclusive),
+ * with elements of <code>other</code>, starting from <code>otherFrom</code> (inclusive).
+ *
+ * @param from the position of the first element to be replaced in the receiver
+ * @param to the position of the last element to be replaced in the receiver
+ * @param other list holding elements to be copied into the receiver.
+ * @param otherFrom position of first element within other list to be copied.
+ */
+public void replaceFromToWithFrom(int from, int to, AbstractShortList other, int otherFrom) {
+ int length=to-from+1;
+ if (length>0) {
+ checkRangeFromTo(from, to, size());
+ checkRangeFromTo(otherFrom,otherFrom+length-1,other.size());
+
+ // unambiguous copy (it may hold other==this)
+ if (from<=otherFrom) {
+ for (; --length >= 0; ) setQuick(from++,other.getQuick(otherFrom++));
+ }
+ else {
+ int otherTo = otherFrom+length-1;
+ for (; --length >= 0; ) setQuick(to--,other.getQuick(otherTo--));
+ }
+
+
+ }
+}
+/**
+* Replaces the part between <code>from</code> (inclusive) and <code>to</code> (inclusive) with the other list's
+* part between <code>otherFrom</code> and <code>otherTo</code>.
+* Powerful (and tricky) method!
+* Both parts need not be of the same size (part A can both be smaller or larger than part B).
+* Parts may overlap.
+* Receiver and other list may (but most not) be identical.
+* If <code>from > to</code>, then inserts other part before <code>from</code>.
+*
+* @param from the first element of the receiver (inclusive)
+* @param to the last element of the receiver (inclusive)
+* @param other the other list (may be identical with receiver)
+* @param otherFrom the first element of the other list (inclusive)
+* @param otherTo the last element of the other list (inclusive)
+*
+* <p><b>Examples:</b><pre>
+* a=[0, 1, 2, 3, 4, 5, 6, 7]
+* b=[50, 60, 70, 80, 90]
+* a.R(...)=a.replaceFromToWithFromTo(...)
+*
+* a.R(3,5,b,0,4)-->[0, 1, 2, 50, 60, 70, 80, 90, 6, 7]
+* a.R(1,6,b,0,4)-->[0, 50, 60, 70, 80, 90, 7]
+* a.R(0,6,b,0,4)-->[50, 60, 70, 80, 90, 7]
+* a.R(3,5,b,1,2)-->[0, 1, 2, 60, 70, 6, 7]
+* a.R(1,6,b,1,2)-->[0, 60, 70, 7]
+* a.R(0,6,b,1,2)-->[60, 70, 7]
+* a.R(5,3,b,0,4)-->[0, 1, 2, 3, 4, 50, 60, 70, 80, 90, 5, 6, 7]
+* a.R(5,0,b,0,4)-->[0, 1, 2, 3, 4, 50, 60, 70, 80, 90, 5, 6, 7]
+* a.R(5,3,b,1,2)-->[0, 1, 2, 3, 4, 60, 70, 5, 6, 7]
+* a.R(5,0,b,1,2)-->[0, 1, 2, 3, 4, 60, 70, 5, 6, 7]
+*
+* Extreme cases:
+* a.R(5,3,b,0,0)-->[0, 1, 2, 3, 4, 50, 5, 6, 7]
+* a.R(5,3,b,4,4)-->[0, 1, 2, 3, 4, 90, 5, 6, 7]
+* a.R(3,5,a,0,1)-->[0, 1, 2, 0, 1, 6, 7]
+* a.R(3,5,a,3,5)-->[0, 1, 2, 3, 4, 5, 6, 7]
+* a.R(3,5,a,4,4)-->[0, 1, 2, 4, 6, 7]
+* a.R(5,3,a,0,4)-->[0, 1, 2, 3, 4, 0, 1, 2, 3, 4, 5, 6, 7]
+* a.R(0,-1,b,0,4)-->[50, 60, 70, 80, 90, 0, 1, 2, 3, 4, 5, 6, 7]
+* a.R(0,-1,a,0,4)-->[0, 1, 2, 3, 4, 0, 1, 2, 3, 4, 5, 6, 7]
+* a.R(8,0,a,0,4)-->[0, 1, 2, 3, 4, 5, 6, 7, 0, 1, 2, 3, 4]
+* </pre>
+*/
+public void replaceFromToWithFromTo(int from, int to, AbstractShortList other, int otherFrom, int otherTo) {
+ if (otherFrom>otherTo) {
+ throw new IndexOutOfBoundsException("otherFrom: "+otherFrom+", otherTo: "+otherTo);
+ }
+
+ if (this==other && to-from!=otherTo-otherFrom) { // avoid stumbling over my own feet
+ replaceFromToWithFromTo(from, to, partFromTo(otherFrom, otherTo), 0, otherTo-otherFrom);
+ return;
+ }
+
+ int length=otherTo-otherFrom+1;
+ int diff=length;
+ int theLast=from-1;
+
+ if (to>=from) {
+ diff -= (to-from+1);
+ theLast=to;
+ }
+
+ if (diff>0) {
+ beforeInsertDummies(theLast+1, diff);
+ }
+ else {
+ if (diff<0) {
+ removeFromTo(theLast+diff, theLast-1);
+ }
+ }
+
+ if (length>0) {
+ replaceFromToWithFrom(from,from+length-1,other,otherFrom);
+ }
+}
+/**
+ * Replaces the part of the receiver starting at <code>from</code> (inclusive) with all the elements of the specified collection.
+ * Does not alter the size of the receiver.
+ * Replaces exactly <tt>Math.max(0,Math.min(size()-from, other.size()))</tt> elements.
+ *
+ * @param from the index at which to copy the first element from the specified collection.
+ * @param other Collection to replace part of the receiver
+ * @exception IndexOutOfBoundsException index is out of range (index < 0 || index >= size()).
+ */
+public void replaceFromWith(int from, java.util.Collection other) {
+ checkRange(from,size());
+ java.util.Iterator e = other.iterator();
+ int index=from;
+ int limit = Math.min(size()-from, other.size());
+ for (int i=0; i<limit; i++)
+ set(index++,((Number) e.next()).shortValue()); //delta
+}
+/**
+* Retains (keeps) only the elements in the receiver that are contained in the specified other list.
+* In other words, removes from the receiver all of its elements that are not contained in the
+* specified other list.
+* @param other the other list to test against.
+* @return <code>true</code> if the receiver changed as a result of the call.
+*/
+public boolean retainAll(AbstractShortList other) {
+ if (other.size()==0) {
+ if (size==0) return false;
+ setSize(0);
+ return true;
+ }
+
+ int limit = other.size()-1;
+ int j=0;
+ for (int i=0; i<size ; i++) {
+ if (other.indexOfFromTo(getQuick(i), 0, limit) >= 0) setQuick(j++, getQuick(i));
+ }
+
+ boolean modified = (j!=size);
+ setSize(j);
+ return modified;
+}
+/**
+ * Reverses the elements of the receiver.
+ * Last becomes first, second last becomes second first, and so on.
+ */
+public void reverse() {
+ short tmp;
+ int limit=size()/2;
+ int j=size()-1;
+
+ for (int i=0; i<limit;) { //swap
+ tmp=getQuick(i);
+ setQuick(i++,getQuick(j));
+ setQuick(j--,tmp);
+ }
+}
+/**
+ * Replaces the element at the specified position in the receiver with the specified element.
+ *
+ * @param index index of element to replace.
+ * @param element element to be stored at the specified position.
+ * @throws IndexOutOfBoundsException if <tt>index < 0 || index >= size()</tt>.
+ */
+public void set(int index, short element) {
+ if (index >= size || index < 0)
+ throw new IndexOutOfBoundsException("Index: "+index+", Size: "+size);
+ setQuick(index,element);
+}
+/**
+ * Replaces the element at the specified position in the receiver with the specified element; <b>WARNING:</b> Does not check preconditions.
+ * Provided with invalid parameters this method may access invalid indexes without throwing any exception!
+ * <b>You should only use this method when you are absolutely sure that the index is within bounds.</b>
+ * Precondition (unchecked): <tt>index >= 0 && index < size()</tt>.
+ *
+ * This method is normally only used internally in large loops where bounds are explicitly checked before the loop and need no be rechecked within the loop.
+ * However, when desperately, you can give this method <tt>public</tt> visibility in subclasses.
+ *
+ * @param index index of element to replace.
+ * @param element element to be stored at the specified position.
+ */
+protected abstract void setQuick(int index, short element);
+/**
+ * Sets the size of the receiver without modifying it otherwise.
+ * This method should not release or allocate new memory but simply set some instance variable like <tt>size</tt>.
+ *
+ * If your subclass overrides and delegates size changing methods to some other object,
+ * you must make sure that those overriding methods not only update the size of the delegate but also of this class.
+ * For example:
+ * public DatabaseList extends AbstractShortList {
+ * ...
+ * public void removeFromTo(int from,int to) {
+ * myDatabase.removeFromTo(from,to);
+ * this.setSizeRaw(size-(to-from+1));
+ * }
+ * }
+ */
+protected void setSizeRaw(int newSize) {
+ size = newSize;
+}
+/**
+ * Randomly permutes the part of the receiver between <code>from</code> (inclusive) and <code>to</code> (inclusive).
+ * @param from the index of the first element (inclusive) to be permuted.
+ * @param to the index of the last element (inclusive) to be permuted.
+ * @exception IndexOutOfBoundsException index is out of range (<tt>size()>0 && (from<0 || from>to || to>=size())</tt>).
+ */
+public void shuffleFromTo(int from, int to) {
+ checkRangeFromTo(from, to, size());
+
+ org.apache.mahout.jet.random.Uniform gen = new org.apache.mahout.jet.random.Uniform(new org.apache.mahout.jet.random.engine.DRand(new java.util.Date()));
+ for (int i=from; i<to; i++) {
+ int random = gen.nextIntFromTo(i, to);
+
+ //swap(i, random)
+ short tmpElement = getQuick(random);
+ setQuick(random,getQuick(i));
+ setQuick(i,tmpElement);
+ }
+}
+/**
+ * Returns the number of elements contained in the receiver.
+ *
+ * @returns the number of elements contained in the receiver.
+ */
+public int size() {
+ return size;
+}
+/**
+ * Returns a list which is a concatenation of <code>times</code> times the receiver.
+ * @param times the number of times the receiver shall be copied.
+ */
+public AbstractShortList times(int times) {
+ AbstractShortList newList = new ShortArrayList(times*size());
+ for (int i=times; --i >= 0; ) {
+ newList.addAllOfFromTo(this,0,size()-1);
+ }
+ return newList;
+}
+/**
+ * Returns a <code>java.util.ArrayList</code> containing all the elements in the receiver.
+ */
+public java.util.ArrayList toList() {
+ int mySize = size();
+ java.util.ArrayList list = new java.util.ArrayList(mySize);
+ for (int i=0; i < mySize; i++) list.add(new Short(get(i)));
+ return list;
+}
+/**
+* Returns a string representation of the receiver, containing
+* the String representation of each element.
+*/
+public String toString() {
+ return org.apache.mahout.colt.Arrays.toString(partFromTo(0, size()-1).elements());
+}
+}
Propchange: lucene/mahout/trunk/matrix/src/main/java/org/apache/mahout/matrix/list/AbstractShortList.java
------------------------------------------------------------------------------
svn:eol-style = native
Added: lucene/mahout/trunk/matrix/src/main/java/org/apache/mahout/matrix/list/BooleanArrayList.java
URL: http://svn.apache.org/viewvc/lucene/mahout/trunk/matrix/src/main/java/org/apache/mahout/matrix/list/BooleanArrayList.java?rev=883365&view=auto
==============================================================================
--- lucene/mahout/trunk/matrix/src/main/java/org/apache/mahout/matrix/list/BooleanArrayList.java (added)
+++ lucene/mahout/trunk/matrix/src/main/java/org/apache/mahout/matrix/list/BooleanArrayList.java Mon Nov 23 15:14:26 2009
@@ -0,0 +1,518 @@
+/*
+Copyright � 1999 CERN - European Organization for Nuclear Research.
+Permission to use, copy, modify, distribute and sell this software and its documentation for any purpose
+is hereby granted without fee, provided that the above copyright notice appear in all copies and
+that both that copyright notice and this permission notice appear in supporting documentation.
+CERN makes no representations about the suitability of this software for any purpose.
+It is provided "as is" without expressed or implied warranty.
+*/
+package org.apache.mahout.colt.list;
+
+import org.apache.mahout.colt.function.BooleanProcedure;
+/**
+Resizable list holding <code>boolean</code> elements; implemented with arrays.
+First see the <a href="package-summary.html">package summary</a> and javadoc <a href="package-tree.html">tree view</a> to get the broad picture.
+*/
+/**
+ * @deprecated until unit tests are in place. Until this time, this class/interface is unsupported.
+ */
+@Deprecated
+public class BooleanArrayList extends AbstractBooleanList {
+ /**
+ * The array buffer into which the elements of the list are stored.
+ * The capacity of the list is the length of this array buffer.
+ * @serial
+ */
+ protected boolean[] elements;
+/**
+ * Constructs an empty list.
+ */
+public BooleanArrayList() {
+ this(10);
+}
+/**
+ * Constructs a list containing the specified elements.
+ * The initial size and capacity of the list is the length of the array.
+ *
+ * <b>WARNING:</b> For efficiency reasons and to keep memory usage low, <b>the array is not copied</b>.
+ * So if subsequently you modify the specified array directly via the [] operator, be sure you know what you're doing.
+ *
+ * @param elements the array to be backed by the the constructed list
+ */
+public BooleanArrayList(boolean[] elements) {
+ elements(elements);
+}
+/**
+ * Constructs an empty list with the specified initial capacity.
+ *
+ * @param initialCapacity the number of elements the receiver can hold without auto-expanding itself by allocating new internal memory.
+ */
+public BooleanArrayList(int initialCapacity) {
+ this(new boolean[initialCapacity]);
+ setSizeRaw(0);
+}
+/**
+ * Appends the specified element to the end of this list.
+ *
+ * @param element element to be appended to this list.
+ */
+public void add(boolean element) {
+ // overridden for performance only.
+ if (size == elements.length) {
+ ensureCapacity(size + 1);
+ }
+ elements[size++] = element;
+}
+/**
+ * Inserts the specified element before the specified position into the receiver.
+ * Shifts the element currently at that position (if any) and
+ * any subsequent elements to the right.
+ *
+ * @param index index before which the specified element is to be inserted (must be in [0,size]).
+ * @param element element to be inserted.
+ * @exception IndexOutOfBoundsException index is out of range (<tt>index < 0 || index > size()</tt>).
+ */
+public void beforeInsert(int index, boolean element) {
+ // overridden for performance only.
+ if (index > size || index < 0)
+ throw new IndexOutOfBoundsException("Index: "+index+", Size: "+size);
+ ensureCapacity(size + 1);
+ System.arraycopy(elements, index, elements, index+1, size-index);
+ elements[index] = element;
+ size++;
+}
+/**
+ * Returns a deep copy of the receiver.
+ *
+ * @return a deep copy of the receiver.
+ */
+public Object clone() {
+ // overridden for performance only.
+ BooleanArrayList clone = new BooleanArrayList((boolean[]) elements.clone());
+ clone.setSizeRaw(size);
+ return clone;
+}
+/**
+ * Returns a deep copy of the receiver; uses <code>clone()</code> and casts the result.
+ *
+ * @return a deep copy of the receiver.
+ */
+public BooleanArrayList copy() {
+ return (BooleanArrayList) clone();
+}
+/**
+ * Sorts the specified range of the receiver into ascending numerical order (<tt>false < true</tt>).
+ *
+ * The sorting algorithm is a count sort. This algorithm offers guaranteed
+ * O(n) performance without auxiliary memory.
+ *
+ * @param from the index of the first element (inclusive) to be sorted.
+ * @param to the index of the last element (inclusive) to be sorted.
+ */
+public void countSortFromTo(int from, int to) {
+ if (size==0) return;
+ checkRangeFromTo(from, to, size);
+
+ boolean[] theElements = elements;
+ int trues = 0;
+ for (int i=from; i<=to;) if (theElements[i++]) trues++;
+
+ int falses = to-from+1-trues;
+ if (falses>0) fillFromToWith(from,from+falses-1,false);
+ if (trues>0) fillFromToWith(from+falses,from+falses-1+trues,true);
+}
+/**
+ * Returns the elements currently stored, including invalid elements between size and capacity, if any.
+ *
+ * <b>WARNING:</b> For efficiency reasons and to keep memory usage low, <b>the array is not copied</b>.
+ * So if subsequently you modify the returned array directly via the [] operator, be sure you know what you're doing.
+ *
+ * @return the elements currently stored.
+ */
+public boolean[] elements() {
+ return elements;
+}
+/**
+ * Sets the receiver's elements to be the specified array (not a copy of it).
+ *
+ * The size and capacity of the list is the length of the array.
+ * <b>WARNING:</b> For efficiency reasons and to keep memory usage low, <b>the array is not copied</b>.
+ * So if subsequently you modify the specified array directly via the [] operator, be sure you know what you're doing.
+ *
+ * @param elements the new elements to be stored.
+ * @return the receiver itself.
+ */
+public AbstractBooleanList elements(boolean[] elements) {
+ this.elements=elements;
+ this.size=elements.length;
+ return this;
+}
+/**
+ * Ensures that the receiver can hold at least the specified number of elements without needing to allocate new internal memory.
+ * If necessary, allocates new internal memory and increases the capacity of the receiver.
+ *
+ * @param minCapacity the desired minimum capacity.
+ */
+public void ensureCapacity(int minCapacity) {
+ elements = org.apache.mahout.colt.Arrays.ensureCapacity(elements,minCapacity);
+}
+/**
+ * Compares the specified Object with the receiver.
+ * Returns true if and only if the specified Object is also an ArrayList of the same type, both Lists have the
+ * same size, and all corresponding pairs of elements in the two Lists are identical.
+ * In other words, two Lists are defined to be equal if they contain the
+ * same elements in the same order.
+ *
+ * @param otherObj the Object to be compared for equality with the receiver.
+ * @return true if the specified Object is equal to the receiver.
+ */
+public boolean equals(Object otherObj) { //delta
+ // overridden for performance only.
+ if (! (otherObj instanceof BooleanArrayList)) return super.equals(otherObj);
+ if (this==otherObj) return true;
+ if (otherObj==null) return false;
+ BooleanArrayList other = (BooleanArrayList) otherObj;
+ if (size()!=other.size()) return false;
+
+ boolean[] theElements = elements();
+ boolean[] otherElements = other.elements();
+ for (int i=size(); --i >= 0; ) {
+ if (theElements[i] != otherElements[i]) return false;
+ }
+ return true;
+}
+/**
+ * Applies a procedure to each element of the receiver, if any.
+ * Starts at index 0, moving rightwards.
+ * @param procedure the procedure to be applied. Stops iteration if the procedure returns <tt>false</tt>, otherwise continues.
+ * @return <tt>false</tt> if the procedure stopped before all elements where iterated over, <tt>true</tt> otherwise.
+ */
+public boolean forEach(BooleanProcedure procedure) {
+ // overridden for performance only.
+ boolean[] theElements = elements;
+ int theSize = size;
+
+ for (int i=0; i<theSize;) if (! procedure.apply(theElements[i++])) return false;
+ return true;
+}
+/**
+ * Returns the element at the specified position in the receiver.
+ *
+ * @param index index of element to return.
+ * @exception IndexOutOfBoundsException index is out of range (index
+ * < 0 || index >= size()).
+ */
+public boolean get(int index) {
+ // overridden for performance only.
+ if (index >= size || index < 0)
+ throw new IndexOutOfBoundsException("Index: "+index+", Size: "+size);
+ return elements[index];
+}
+/**
+ * Returns the element at the specified position in the receiver; <b>WARNING:</b> Does not check preconditions.
+ * Provided with invalid parameters this method may return invalid elements without throwing any exception!
+ * <b>You should only use this method when you are absolutely sure that the index is within bounds.</b>
+ * Precondition (unchecked): <tt>index >= 0 && index < size()</tt>.
+ *
+ * @param index index of element to return.
+ */
+public boolean getQuick(int index) {
+ return elements[index];
+}
+/**
+ * Returns the index of the first occurrence of the specified
+ * element. Returns <code>-1</code> if the receiver does not contain this element.
+ * Searches between <code>from</code>, inclusive and <code>to</code>, inclusive.
+ * Tests for identity.
+ *
+ * @param element element to search for.
+ * @param from the leftmost search position, inclusive.
+ * @param to the rightmost search position, inclusive.
+ * @return the index of the first occurrence of the element in the receiver; returns <code>-1</code> if the element is not found.
+ * @exception IndexOutOfBoundsException index is out of range (<tt>size()>0 && (from<0 || from>to || to>=size())</tt>).
+ */
+public int indexOfFromTo(boolean element, int from, int to) {
+ // overridden for performance only.
+ if (size==0) return -1;
+ checkRangeFromTo(from, to, size);
+
+ boolean[] theElements = elements;
+ for (int i = from ; i <= to; i++) {
+ if (element==theElements[i]) {return i;} //found
+ }
+ return -1; //not found
+}
+/**
+ * Returns the index of the last occurrence of the specified
+ * element. Returns <code>-1</code> if the receiver does not contain this element.
+ * Searches beginning at <code>to</code>, inclusive until <code>from</code>, inclusive.
+ * Tests for identity.
+ *
+ * @param element element to search for.
+ * @param from the leftmost search position, inclusive.
+ * @param to the rightmost search position, inclusive.
+ * @return the index of the last occurrence of the element in the receiver; returns <code>-1</code> if the element is not found.
+ * @exception IndexOutOfBoundsException index is out of range (<tt>size()>0 && (from<0 || from>to || to>=size())</tt>).
+ */
+public int lastIndexOfFromTo(boolean element, int from, int to) {
+ // overridden for performance only.
+ if (size==0) return -1;
+ checkRangeFromTo(from, to, size);
+
+ boolean[] theElements = elements;
+ for (int i = to ; i >= from; i--) {
+ if (element==theElements[i]) {return i;} //found
+ }
+ return -1; //not found
+}
+/**
+ * Sorts the specified range of the receiver into ascending order (<tt>false < true</tt>).
+ *
+ * The sorting algorithm is <b>not</b> a mergesort, but rather a countsort.
+ * This algorithm offers guaranteed O(n) performance.
+ *
+ * @param from the index of the first element (inclusive) to be sorted.
+ * @param to the index of the last element (inclusive) to be sorted.
+ * @exception IndexOutOfBoundsException index is out of range (<tt>size()>0 && (from<0 || from>to || to>=size())</tt>).
+ */
+public void mergeSortFromTo(int from, int to) {
+ countSortFromTo(from, to);
+}
+/**
+ * Returns a new list of the part of the receiver between <code>from</code>, inclusive, and <code>to</code>, inclusive.
+ * @param from the index of the first element (inclusive).
+ * @param to the index of the last element (inclusive).
+ * @return a new list
+ * @exception IndexOutOfBoundsException index is out of range (<tt>size()>0 && (from<0 || from>to || to>=size())</tt>).
+ */
+public AbstractBooleanList partFromTo(int from, int to) {
+ if (size==0) return new BooleanArrayList(0);
+
+ checkRangeFromTo(from, to, size);
+
+ boolean[] part = new boolean[to-from+1];
+ System.arraycopy(elements, from, part, 0, to-from+1);
+ return new BooleanArrayList(part);
+}
+/**
+ * Sorts the specified range of the receiver into ascending order (<tt>false < true</tt>).
+ *
+ * The sorting algorithm is <b>not</b> a quicksort, but rather a countsort.
+ * This algorithm offers guaranteed O(n) performance.
+ *
+ * @param from the index of the first element (inclusive) to be sorted.
+ * @param to the index of the last element (inclusive) to be sorted.
+ * @exception IndexOutOfBoundsException index is out of range (<tt>size()>0 && (from<0 || from>to || to>=size())</tt>).
+ */
+public void quickSortFromTo(int from, int to) {
+ countSortFromTo(from, to);
+}
+/**
+* Removes from the receiver all elements that are contained in the specified list.
+* Tests for identity.
+*
+* @param other the other list.
+* @return <code>true</code> if the receiver changed as a result of the call.
+*/
+public boolean removeAll(AbstractBooleanList other) {
+ // overridden for performance only.
+ if (! (other instanceof BooleanArrayList)) return super.removeAll(other);
+
+ /* There are two possibilities to do the thing
+ a) use other.indexOf(...)
+ b) sort other, then use other.binarySearch(...)
+
+ Let's try to figure out which one is faster. Let M=size, N=other.size, then
+ a) takes O(M*N) steps
+ b) takes O(N*logN + M*logN) steps (sorting is O(N*logN) and binarySearch is O(logN))
+
+ Hence, if N*logN + M*logN < M*N, we use b) otherwise we use a).
+ */
+ if (other.size()==0) {return false;} //nothing to do
+ int limit = other.size()-1;
+ int j=0;
+ boolean[] theElements = elements;
+ int mySize = size();
+
+ double N=(double) other.size();
+ double M=(double) mySize;
+ if ( (N+M)* org.apache.mahout.jet.math.Arithmetic.log2(N) < M*N ) {
+ // it is faster to sort other before searching in it
+ BooleanArrayList sortedList = (BooleanArrayList) other.clone();
+ sortedList.quickSort();
+
+ for (int i=0; i<mySize ; i++) {
+ if (sortedList.binarySearchFromTo(theElements[i], 0, limit) < 0) theElements[j++]=theElements[i];
+ }
+ }
+ else {
+ // it is faster to search in other without sorting
+ for (int i=0; i<mySize ; i++) {
+ if (other.indexOfFromTo(theElements[i], 0, limit) < 0) theElements[j++]=theElements[i];
+ }
+ }
+
+ boolean modified = (j!=mySize);
+ setSize(j);
+ return modified;
+}
+/**
+ * Replaces a number of elements in the receiver with the same number of elements of another list.
+ * Replaces elements in the receiver, between <code>from</code> (inclusive) and <code>to</code> (inclusive),
+ * with elements of <code>other</code>, starting from <code>otherFrom</code> (inclusive).
+ *
+ * @param from the position of the first element to be replaced in the receiver
+ * @param to the position of the last element to be replaced in the receiver
+ * @param other list holding elements to be copied into the receiver.
+ * @param otherFrom position of first element within other list to be copied.
+ */
+public void replaceFromToWithFrom(int from, int to, AbstractBooleanList other, int otherFrom) {
+ // overridden for performance only.
+ if (! (other instanceof BooleanArrayList)) {
+ // slower
+ super.replaceFromToWithFrom(from,to,other,otherFrom);
+ return;
+ }
+ int length=to-from+1;
+ if (length>0) {
+ checkRangeFromTo(from, to, size());
+ checkRangeFromTo(otherFrom,otherFrom+length-1,other.size());
+ System.arraycopy(((BooleanArrayList) other).elements, otherFrom, elements, from, length);
+ }
+}
+/**
+* Retains (keeps) only the elements in the receiver that are contained in the specified other list.
+* In other words, removes from the receiver all of its elements that are not contained in the
+* specified other list.
+* @param other the other list to test against.
+* @return <code>true</code> if the receiver changed as a result of the call.
+*/
+public boolean retainAll(AbstractBooleanList other) {
+ // overridden for performance only.
+ if (! (other instanceof BooleanArrayList)) return super.retainAll(other);
+
+ /* There are two possibilities to do the thing
+ a) use other.indexOf(...)
+ b) sort other, then use other.binarySearch(...)
+
+ Let's try to figure out which one is faster. Let M=size, N=other.size, then
+ a) takes O(M*N) steps
+ b) takes O(N*logN + M*logN) steps (sorting is O(N*logN) and binarySearch is O(logN))
+
+ Hence, if N*logN + M*logN < M*N, we use b) otherwise we use a).
+ */
+ int limit = other.size()-1;
+ int j=0;
+ boolean[] theElements = elements;
+ int mySize = size();
+
+ double N=(double) other.size();
+ double M=(double) mySize;
+ if ( (N+M)* org.apache.mahout.jet.math.Arithmetic.log2(N) < M*N ) {
+ // it is faster to sort other before searching in it
+ BooleanArrayList sortedList = (BooleanArrayList) other.clone();
+ sortedList.quickSort();
+
+ for (int i=0; i<mySize ; i++) {
+ if (sortedList.binarySearchFromTo(theElements[i], 0, limit) >= 0) theElements[j++]=theElements[i];
+ }
+ }
+ else {
+ // it is faster to search in other without sorting
+ for (int i=0; i<mySize ; i++) {
+ if (other.indexOfFromTo(theElements[i], 0, limit) >= 0) theElements[j++]=theElements[i];
+ }
+ }
+
+ boolean modified = (j!=mySize);
+ setSize(j);
+ return modified;
+}
+/**
+ * Reverses the elements of the receiver.
+ * Last becomes first, second last becomes second first, and so on.
+ */
+public void reverse() {
+ // overridden for performance only.
+ boolean tmp;
+ int limit=size/2;
+ int j=size-1;
+
+ boolean[] theElements = elements;
+ for (int i=0; i<limit;) { //swap
+ tmp=theElements[i];
+ theElements[i++]=theElements[j];
+ theElements[j--]=tmp;
+ }
+}
+/**
+ * Replaces the element at the specified position in the receiver with the specified element.
+ *
+ * @param index index of element to replace.
+ * @param element element to be stored at the specified position.
+ * @exception IndexOutOfBoundsException index is out of range (index
+ * < 0 || index >= size()).
+ */
+public void set(int index, boolean element) {
+ // overridden for performance only.
+ if (index >= size || index < 0)
+ throw new IndexOutOfBoundsException("Index: "+index+", Size: "+size);
+ elements[index] = element;
+}
+/**
+ * Replaces the element at the specified position in the receiver with the specified element; <b>WARNING:</b> Does not check preconditions.
+ * Provided with invalid parameters this method may access invalid indexes without throwing any exception!
+ * <b>You should only use this method when you are absolutely sure that the index is within bounds.</b>
+ * Precondition (unchecked): <tt>index >= 0 && index < size()</tt>.
+ *
+ * @param index index of element to replace.
+ * @param element element to be stored at the specified position.
+ */
+public void setQuick(int index, boolean element) {
+ elements[index] = element;
+}
+/**
+ * Randomly permutes the part of the receiver between <code>from</code> (inclusive) and <code>to</code> (inclusive).
+ * @param from the index of the first element (inclusive) to be permuted.
+ * @param to the index of the last element (inclusive) to be permuted.
+ * @exception IndexOutOfBoundsException index is out of range (<tt>size()>0 && (from<0 || from>to || to>=size())</tt>).
+ */
+public void shuffleFromTo(int from, int to) {
+ // overridden for performance only.
+ if (size==0) {return;}
+ checkRangeFromTo(from, to, size);
+
+ org.apache.mahout.jet.random.Uniform gen = new org.apache.mahout.jet.random.Uniform(new org.apache.mahout.jet.random.engine.DRand(new java.util.Date()));
+ boolean tmpElement;
+ boolean[] theElements = elements;
+ int random;
+ for (int i=from; i<to; i++) {
+ random = gen.nextIntFromTo(i, to);
+
+ //swap(i, random)
+ tmpElement = theElements[random];
+ theElements[random]=theElements[i];
+ theElements[i]=tmpElement;
+ }
+}
+/**
+ * Sorts the specified range of the receiver into ascending order.
+ *
+ * The sorting algorithm is countsort.
+ *
+ * @param from the index of the first element (inclusive) to be sorted.
+ * @param to the index of the last element (inclusive) to be sorted.
+ * @exception IndexOutOfBoundsException index is out of range (<tt>size()>0 && (from<0 || from>to || to>=size())</tt>).
+ */
+public void sortFromTo(int from, int to) {
+ countSortFromTo(from, to);
+}
+/**
+ * Trims the capacity of the receiver to be the receiver's current
+ * size. Releases any superfluos internal memory. An application can use this operation to minimize the
+ * storage of the receiver.
+ */
+public void trimToSize() {
+ elements = org.apache.mahout.colt.Arrays.trimToCapacity(elements,size());
+}
+}
Propchange: lucene/mahout/trunk/matrix/src/main/java/org/apache/mahout/matrix/list/BooleanArrayList.java
------------------------------------------------------------------------------
svn:eol-style = native
Added: lucene/mahout/trunk/matrix/src/main/java/org/apache/mahout/matrix/list/ByteArrayList.java
URL: http://svn.apache.org/viewvc/lucene/mahout/trunk/matrix/src/main/java/org/apache/mahout/matrix/list/ByteArrayList.java?rev=883365&view=auto
==============================================================================
--- lucene/mahout/trunk/matrix/src/main/java/org/apache/mahout/matrix/list/ByteArrayList.java (added)
+++ lucene/mahout/trunk/matrix/src/main/java/org/apache/mahout/matrix/list/ByteArrayList.java Mon Nov 23 15:14:26 2009
@@ -0,0 +1,581 @@
+/*
+Copyright � 1999 CERN - European Organization for Nuclear Research.
+Permission to use, copy, modify, distribute and sell this software and its documentation for any purpose
+is hereby granted without fee, provided that the above copyright notice appear in all copies and
+that both that copyright notice and this permission notice appear in supporting documentation.
+CERN makes no representations about the suitability of this software for any purpose.
+It is provided "as is" without expressed or implied warranty.
+*/
+package org.apache.mahout.colt.list;
+
+import org.apache.mahout.colt.function.ByteProcedure;
+/**
+Resizable list holding <code>byte</code> elements; implemented with arrays.
+First see the <a href="package-summary.html">package summary</a> and javadoc <a href="package-tree.html">tree view</a> to get the broad picture.
+*/
+/**
+ * @deprecated until unit tests are in place. Until this time, this class/interface is unsupported.
+ */
+@Deprecated
+public class ByteArrayList extends AbstractByteList {
+ /**
+ * The array buffer into which the elements of the list are stored.
+ * The capacity of the list is the length of this array buffer.
+ * @serial
+ */
+ protected byte[] elements;
+/**
+ * Constructs an empty list.
+ */
+public ByteArrayList() {
+ this(10);
+}
+/**
+ * Constructs a list containing the specified elements.
+ * The initial size and capacity of the list is the length of the array.
+ *
+ * <b>WARNING:</b> For efficiency reasons and to keep memory usage low, <b>the array is not copied</b>.
+ * So if subsequently you modify the specified array directly via the [] operator, be sure you know what you're doing.
+ *
+ * @param elements the array to be backed by the the constructed list
+ */
+public ByteArrayList(byte[] elements) {
+ elements(elements);
+}
+/**
+ * Constructs an empty list with the specified initial capacity.
+ *
+ * @param initialCapacity the number of elements the receiver can hold without auto-expanding itself by allocating new internal memory.
+ */
+public ByteArrayList(int initialCapacity) {
+ this(new byte[initialCapacity]);
+ setSizeRaw(0);
+}
+/**
+ * Appends the specified element to the end of this list.
+ *
+ * @param element element to be appended to this list.
+ */
+public void add(byte element) {
+ // overridden for performance only.
+ if (size == elements.length) {
+ ensureCapacity(size + 1);
+ }
+ elements[size++] = element;
+}
+/**
+ * Inserts the specified element before the specified position into the receiver.
+ * Shifts the element currently at that position (if any) and
+ * any subsequent elements to the right.
+ *
+ * @param index index before which the specified element is to be inserted (must be in [0,size]).
+ * @param element element to be inserted.
+ * @exception IndexOutOfBoundsException index is out of range (<tt>index < 0 || index > size()</tt>).
+ */
+public void beforeInsert(int index, byte element) {
+ // overridden for performance only.
+ if (index > size || index < 0)
+ throw new IndexOutOfBoundsException("Index: "+index+", Size: "+size);
+ ensureCapacity(size + 1);
+ System.arraycopy(elements, index, elements, index+1, size-index);
+ elements[index] = element;
+ size++;
+}
+/**
+ * Searches the receiver for the specified value using
+ * the binary search algorithm. The receiver must <strong>must</strong> be
+ * sorted (as by the sort method) prior to making this call. If
+ * it is not sorted, the results are undefined: in particular, the call
+ * may enter an infinite loop. If the receiver contains multiple elements
+ * equal to the specified object, there is no guarantee which instance
+ * will be found.
+ *
+ * @param key the value to be searched for.
+ * @param from the leftmost search position, inclusive.
+ * @param to the rightmost search position, inclusive.
+ * @return index of the search key, if it is contained in the receiver;
+ * otherwise, <tt>(-(<i>insertion point</i>) - 1)</tt>. The <i>insertion
+ * point</i> is defined as the the point at which the value would
+ * be inserted into the receiver: the index of the first
+ * element greater than the key, or <tt>receiver.size()</tt>, if all
+ * elements in the receiver are less than the specified key. Note
+ * that this guarantees that the return value will be >= 0 if
+ * and only if the key is found.
+ * @see org.apache.mahout.colt.Sorting
+ * @see java.util.Arrays
+ */
+public int binarySearchFromTo(byte key, int from, int to) {
+ return org.apache.mahout.colt.Sorting.binarySearchFromTo(this.elements,key,from,to);
+}
+/**
+ * Returns a deep copy of the receiver.
+ *
+ * @return a deep copy of the receiver.
+ */
+public Object clone() {
+ // overridden for performance only.
+ ByteArrayList clone = new ByteArrayList((byte[]) elements.clone());
+ clone.setSizeRaw(size);
+ return clone;
+}
+/**
+ * Returns a deep copy of the receiver; uses <code>clone()</code> and casts the result.
+ *
+ * @return a deep copy of the receiver.
+ */
+public ByteArrayList copy() {
+ return (ByteArrayList) clone();
+}
+/**
+ * Sorts the specified range of the receiver into ascending numerical order.
+ *
+ * The sorting algorithm is a count sort. This algorithm offers guaranteed
+ * O(Max(n,256)) performance.
+ *
+ * @param from the index of the first element (inclusive) to be sorted.
+ * @param to the index of the last element (inclusive) to be sorted.
+ */
+public void countSortFromTo(int from, int to) {
+ if (size==0) return;
+ checkRangeFromTo(from, to, size);
+
+ final int min = - (int)Byte.MIN_VALUE;
+ final int range = min + Byte.MAX_VALUE + 1;
+ byte[] theElements = elements;
+ int[] counts = new int[range];
+
+ for (int i=from; i<=to; i++) counts[theElements[i]+min]++;
+
+ int fromIndex = from;
+ byte val = Byte.MIN_VALUE;
+ for (int i=0; i<range; i++, val++) {
+ int c=counts[i];
+ if (c>0) {
+ if (c==1) theElements[fromIndex++]=val;
+ else {
+ int toIndex = fromIndex+c-1;
+ fillFromToWith(fromIndex,toIndex,val);
+ fromIndex = toIndex+1;
+ }
+ }
+ }
+}
+ /**
+ * Sorts the specified range of the receiver into ascending numerical order.
+ *
+ * The sorting algorithm is a count sort. This algorithm offers guaranteed
+ * <dt>Performance: O(Max(n,max-min+1)).
+ * <dt>Space requirements: int[max-min+1] buffer.
+ * <p>This algorithm is only applicable if max-min+1 is not large!
+ * But if applicable, it usually outperforms quicksort by a factor of 3-4.
+ *
+ * @param from the index of the first element (inclusive) to be sorted.
+ * @param to the index of the last element (inclusive) to be sorted.
+ * @param min the smallest element contained in the range.
+ * @param max the largest element contained in the range.
+ */
+protected void countSortFromTo(int from, int to, byte min, byte max) {
+ if (size==0) return;
+ checkRangeFromTo(from, to, size);
+
+ final int width = (int) (max-min+1);
+
+ int[] counts = new int[width];
+ byte[] theElements = elements;
+ for (int i=from; i<=to; ) counts[(int)(theElements[i++]-min)]++;
+
+ int fromIndex = from;
+ byte val = min;
+ for (int i=0; i<width; i++, val++) {
+ int c = counts[i];
+ if (c>0) {
+ if (c==1) theElements[fromIndex++]=val;
+ else {
+ int toIndex = fromIndex + c - 1;
+ fillFromToWith(fromIndex,toIndex,val);
+ fromIndex = toIndex + 1;
+ }
+ }
+ }
+}
+/**
+ * Returns the elements currently stored, including invalid elements between size and capacity, if any.
+ *
+ * <b>WARNING:</b> For efficiency reasons and to keep memory usage low, <b>the array is not copied</b>.
+ * So if subsequently you modify the returned array directly via the [] operator, be sure you know what you're doing.
+ *
+ * @return the elements currently stored.
+ */
+public byte[] elements() {
+ return elements;
+}
+/**
+ * Sets the receiver's elements to be the specified array (not a copy of it).
+ *
+ * The size and capacity of the list is the length of the array.
+ * <b>WARNING:</b> For efficiency reasons and to keep memory usage low, <b>the array is not copied</b>.
+ * So if subsequently you modify the specified array directly via the [] operator, be sure you know what you're doing.
+ *
+ * @param elements the new elements to be stored.
+ * @return the receiver itself.
+ */
+public AbstractByteList elements(byte[] elements) {
+ this.elements=elements;
+ this.size=elements.length;
+ return this;
+}
+/**
+ * Ensures that the receiver can hold at least the specified number of elements without needing to allocate new internal memory.
+ * If necessary, allocates new internal memory and increases the capacity of the receiver.
+ *
+ * @param minCapacity the desired minimum capacity.
+ */
+public void ensureCapacity(int minCapacity) {
+ elements = org.apache.mahout.colt.Arrays.ensureCapacity(elements,minCapacity);
+}
+/**
+ * Compares the specified Object with the receiver.
+ * Returns true if and only if the specified Object is also an ArrayList of the same type, both Lists have the
+ * same size, and all corresponding pairs of elements in the two Lists are identical.
+ * In other words, two Lists are defined to be equal if they contain the
+ * same elements in the same order.
+ *
+ * @param otherObj the Object to be compared for equality with the receiver.
+ * @return true if the specified Object is equal to the receiver.
+ */
+public boolean equals(Object otherObj) { //delta
+ // overridden for performance only.
+ if (! (otherObj instanceof ByteArrayList)) return super.equals(otherObj);
+ if (this==otherObj) return true;
+ if (otherObj==null) return false;
+ ByteArrayList other = (ByteArrayList) otherObj;
+ if (size()!=other.size()) return false;
+
+ byte[] theElements = elements();
+ byte[] otherElements = other.elements();
+ for (int i=size(); --i >= 0; ) {
+ if (theElements[i] != otherElements[i]) return false;
+ }
+ return true;
+}
+/**
+ * Applies a procedure to each element of the receiver, if any.
+ * Starts at index 0, moving rightwards.
+ * @param procedure the procedure to be applied. Stops iteration if the procedure returns <tt>false</tt>, otherwise continues.
+ * @return <tt>false</tt> if the procedure stopped before all elements where iterated over, <tt>true</tt> otherwise.
+ */
+public boolean forEach(ByteProcedure procedure) {
+ // overridden for performance only.
+ byte[] theElements = elements;
+ int theSize = size;
+
+ for (int i=0; i<theSize;) if (! procedure.apply(theElements[i++])) return false;
+ return true;
+}
+/**
+ * Returns the element at the specified position in the receiver.
+ *
+ * @param index index of element to return.
+ * @exception IndexOutOfBoundsException index is out of range (index
+ * < 0 || index >= size()).
+ */
+public byte get(int index) {
+ // overridden for performance only.
+ if (index >= size || index < 0)
+ throw new IndexOutOfBoundsException("Index: "+index+", Size: "+size);
+ return elements[index];
+}
+/**
+ * Returns the element at the specified position in the receiver; <b>WARNING:</b> Does not check preconditions.
+ * Provided with invalid parameters this method may return invalid elements without throwing any exception!
+ * <b>You should only use this method when you are absolutely sure that the index is within bounds.</b>
+ * Precondition (unchecked): <tt>index >= 0 && index < size()</tt>.
+ *
+ * @param index index of element to return.
+ */
+public byte getQuick(int index) {
+ return elements[index];
+}
+/**
+ * Returns the index of the first occurrence of the specified
+ * element. Returns <code>-1</code> if the receiver does not contain this element.
+ * Searches between <code>from</code>, inclusive and <code>to</code>, inclusive.
+ * Tests for identity.
+ *
+ * @param element element to search for.
+ * @param from the leftmost search position, inclusive.
+ * @param to the rightmost search position, inclusive.
+ * @return the index of the first occurrence of the element in the receiver; returns <code>-1</code> if the element is not found.
+ * @exception IndexOutOfBoundsException index is out of range (<tt>size()>0 && (from<0 || from>to || to>=size())</tt>).
+ */
+public int indexOfFromTo(byte element, int from, int to) {
+ // overridden for performance only.
+ if (size==0) return -1;
+ checkRangeFromTo(from, to, size);
+
+ byte[] theElements = elements;
+ for (int i = from ; i <= to; i++) {
+ if (element==theElements[i]) {return i;} //found
+ }
+ return -1; //not found
+}
+/**
+ * Returns the index of the last occurrence of the specified
+ * element. Returns <code>-1</code> if the receiver does not contain this element.
+ * Searches beginning at <code>to</code>, inclusive until <code>from</code>, inclusive.
+ * Tests for identity.
+ *
+ * @param element element to search for.
+ * @param from the leftmost search position, inclusive.
+ * @param to the rightmost search position, inclusive.
+ * @return the index of the last occurrence of the element in the receiver; returns <code>-1</code> if the element is not found.
+ * @exception IndexOutOfBoundsException index is out of range (<tt>size()>0 && (from<0 || from>to || to>=size())</tt>).
+ */
+public int lastIndexOfFromTo(byte element, int from, int to) {
+ // overridden for performance only.
+ if (size==0) return -1;
+ checkRangeFromTo(from, to, size);
+
+ byte[] theElements = elements;
+ for (int i = to ; i >= from; i--) {
+ if (element==theElements[i]) {return i;} //found
+ }
+ return -1; //not found
+}
+/**
+ * Returns a new list of the part of the receiver between <code>from</code>, inclusive, and <code>to</code>, inclusive.
+ * @param from the index of the first element (inclusive).
+ * @param to the index of the last element (inclusive).
+ * @return a new list
+ * @exception IndexOutOfBoundsException index is out of range (<tt>size()>0 && (from<0 || from>to || to>=size())</tt>).
+ */
+public AbstractByteList partFromTo(int from, int to) {
+ if (size==0) return new ByteArrayList(0);
+
+ checkRangeFromTo(from, to, size);
+
+ byte[] part = new byte[to-from+1];
+ System.arraycopy(elements, from, part, 0, to-from+1);
+ return new ByteArrayList(part);
+}
+/**
+* Removes from the receiver all elements that are contained in the specified list.
+* Tests for identity.
+*
+* @param other the other list.
+* @return <code>true</code> if the receiver changed as a result of the call.
+*/
+public boolean removeAll(AbstractByteList other) {
+ // overridden for performance only.
+ if (! (other instanceof ByteArrayList)) return super.removeAll(other);
+
+ /* There are two possibilities to do the thing
+ a) use other.indexOf(...)
+ b) sort other, then use other.binarySearch(...)
+
+ Let's try to figure out which one is faster. Let M=size, N=other.size, then
+ a) takes O(M*N) steps
+ b) takes O(N*logN + M*logN) steps (sorting is O(N*logN) and binarySearch is O(logN))
+
+ Hence, if N*logN + M*logN < M*N, we use b) otherwise we use a).
+ */
+ if (other.size()==0) {return false;} //nothing to do
+ int limit = other.size()-1;
+ int j=0;
+ byte[] theElements = elements;
+ int mySize = size();
+
+ double N=(double) other.size();
+ double M=(double) mySize;
+ if ( (N+M)* org.apache.mahout.jet.math.Arithmetic.log2(N) < M*N ) {
+ // it is faster to sort other before searching in it
+ ByteArrayList sortedList = (ByteArrayList) other.clone();
+ sortedList.quickSort();
+
+ for (int i=0; i<mySize ; i++) {
+ if (sortedList.binarySearchFromTo(theElements[i], 0, limit) < 0) theElements[j++]=theElements[i];
+ }
+ }
+ else {
+ // it is faster to search in other without sorting
+ for (int i=0; i<mySize ; i++) {
+ if (other.indexOfFromTo(theElements[i], 0, limit) < 0) theElements[j++]=theElements[i];
+ }
+ }
+
+ boolean modified = (j!=mySize);
+ setSize(j);
+ return modified;
+}
+/**
+ * Replaces a number of elements in the receiver with the same number of elements of another list.
+ * Replaces elements in the receiver, between <code>from</code> (inclusive) and <code>to</code> (inclusive),
+ * with elements of <code>other</code>, starting from <code>otherFrom</code> (inclusive).
+ *
+ * @param from the position of the first element to be replaced in the receiver
+ * @param to the position of the last element to be replaced in the receiver
+ * @param other list holding elements to be copied into the receiver.
+ * @param otherFrom position of first element within other list to be copied.
+ */
+public void replaceFromToWithFrom(int from, int to, AbstractByteList other, int otherFrom) {
+ // overridden for performance only.
+ if (! (other instanceof ByteArrayList)) {
+ // slower
+ super.replaceFromToWithFrom(from,to,other,otherFrom);
+ return;
+ }
+ int length=to-from+1;
+ if (length>0) {
+ checkRangeFromTo(from, to, size());
+ checkRangeFromTo(otherFrom,otherFrom+length-1,other.size());
+ System.arraycopy(((ByteArrayList) other).elements, otherFrom, elements, from, length);
+ }
+}
+/**
+* Retains (keeps) only the elements in the receiver that are contained in the specified other list.
+* In other words, removes from the receiver all of its elements that are not contained in the
+* specified other list.
+* @param other the other list to test against.
+* @return <code>true</code> if the receiver changed as a result of the call.
+*/
+public boolean retainAll(AbstractByteList other) {
+ // overridden for performance only.
+ if (! (other instanceof ByteArrayList)) return super.retainAll(other);
+
+ /* There are two possibilities to do the thing
+ a) use other.indexOf(...)
+ b) sort other, then use other.binarySearch(...)
+
+ Let's try to figure out which one is faster. Let M=size, N=other.size, then
+ a) takes O(M*N) steps
+ b) takes O(N*logN + M*logN) steps (sorting is O(N*logN) and binarySearch is O(logN))
+
+ Hence, if N*logN + M*logN < M*N, we use b) otherwise we use a).
+ */
+ int limit = other.size()-1;
+ int j=0;
+ byte[] theElements = elements;
+ int mySize = size();
+
+ double N=(double) other.size();
+ double M=(double) mySize;
+ if ( (N+M)* org.apache.mahout.jet.math.Arithmetic.log2(N) < M*N ) {
+ // it is faster to sort other before searching in it
+ ByteArrayList sortedList = (ByteArrayList) other.clone();
+ sortedList.quickSort();
+
+ for (int i=0; i<mySize ; i++) {
+ if (sortedList.binarySearchFromTo(theElements[i], 0, limit) >= 0) theElements[j++]=theElements[i];
+ }
+ }
+ else {
+ // it is faster to search in other without sorting
+ for (int i=0; i<mySize ; i++) {
+ if (other.indexOfFromTo(theElements[i], 0, limit) >= 0) theElements[j++]=theElements[i];
+ }
+ }
+
+ boolean modified = (j!=mySize);
+ setSize(j);
+ return modified;
+}
+/**
+ * Reverses the elements of the receiver.
+ * Last becomes first, second last becomes second first, and so on.
+ */
+public void reverse() {
+ // overridden for performance only.
+ byte tmp;
+ int limit=size/2;
+ int j=size-1;
+
+ byte[] theElements = elements;
+ for (int i=0; i<limit;) { //swap
+ tmp=theElements[i];
+ theElements[i++]=theElements[j];
+ theElements[j--]=tmp;
+ }
+}
+/**
+ * Replaces the element at the specified position in the receiver with the specified element.
+ *
+ * @param index index of element to replace.
+ * @param element element to be stored at the specified position.
+ * @exception IndexOutOfBoundsException index is out of range (index
+ * < 0 || index >= size()).
+ */
+public void set(int index, byte element) {
+ // overridden for performance only.
+ if (index >= size || index < 0)
+ throw new IndexOutOfBoundsException("Index: "+index+", Size: "+size);
+ elements[index] = element;
+}
+/**
+ * Replaces the element at the specified position in the receiver with the specified element; <b>WARNING:</b> Does not check preconditions.
+ * Provided with invalid parameters this method may access invalid indexes without throwing any exception!
+ * <b>You should only use this method when you are absolutely sure that the index is within bounds.</b>
+ * Precondition (unchecked): <tt>index >= 0 && index < size()</tt>.
+ *
+ * @param index index of element to replace.
+ * @param element element to be stored at the specified position.
+ */
+public void setQuick(int index, byte element) {
+ elements[index] = element;
+}
+/**
+ * Randomly permutes the part of the receiver between <code>from</code> (inclusive) and <code>to</code> (inclusive).
+ * @param from the index of the first element (inclusive) to be permuted.
+ * @param to the index of the last element (inclusive) to be permuted.
+ * @exception IndexOutOfBoundsException index is out of range (<tt>size()>0 && (from<0 || from>to || to>=size())</tt>).
+ */
+public void shuffleFromTo(int from, int to) {
+ // overridden for performance only.
+ if (size==0) {return;}
+ checkRangeFromTo(from, to, size);
+
+ org.apache.mahout.jet.random.Uniform gen = new org.apache.mahout.jet.random.Uniform(new org.apache.mahout.jet.random.engine.DRand(new java.util.Date()));
+ byte tmpElement;
+ byte[] theElements = elements;
+ int random;
+ for (int i=from; i<to; i++) {
+ random = gen.nextIntFromTo(i, to);
+
+ //swap(i, random)
+ tmpElement = theElements[random];
+ theElements[random]=theElements[i];
+ theElements[i]=tmpElement;
+ }
+}
+/**
+ * Sorts the specified range of the receiver into ascending order.
+ *
+ * The sorting algorithm is countsort.
+ *
+ * @param from the index of the first element (inclusive) to be sorted.
+ * @param to the index of the last element (inclusive) to be sorted.
+ * @exception IndexOutOfBoundsException index is out of range (<tt>size()>0 && (from<0 || from>to || to>=size())</tt>).
+ */
+public void sortFromTo(int from, int to) {
+ // try to figure out which option is fastest.
+ double N = to - from + 1;
+ double quickSortEstimate = N * Math.log(N)/0.6931471805599453; // O(N*log(N,base=2)) ; ln(2)=0.6931471805599453
+
+ double width = 256;
+ double countSortEstimate = Math.max(width,N); // O(Max(width,N))
+
+ if (countSortEstimate < quickSortEstimate) {
+ countSortFromTo(from, to);
+ }
+ else {
+ quickSortFromTo(from, to);
+ }
+}
+/**
+ * Trims the capacity of the receiver to be the receiver's current
+ * size. Releases any superfluos internal memory. An application can use this operation to minimize the
+ * storage of the receiver.
+ */
+public void trimToSize() {
+ elements = org.apache.mahout.colt.Arrays.trimToCapacity(elements,size());
+}
+}
Propchange: lucene/mahout/trunk/matrix/src/main/java/org/apache/mahout/matrix/list/ByteArrayList.java
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